CCK
Cholecystokinin precursor (CCK) [Contains: Cholecystokinin-58 (CCK58); Cholecystokinin-58 desnonopeptide ((1-49)-CCK58); Cholecystokinin-39 (CCK39); Cholecystokinin-33 (CCK33); Cholecystokinin-25 (CCK25); Cholecystokinin-18 (CCK18); Cholecystokinin-12 (CCK12); Cholecystokinin-8 (CCK8); Cholecystokinin-7 (CCK7); Cholecystokinin-5 (CCK5)]
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Intervertebral disc degeneration (IDD) represents major cause of low back pain. Quercetin (QUE) is one of the approved senolytic agents. In this study, we evaluated the protective effects of QUE on IDD development and its underlying mechanism. Effects of senolytic agent QUE on the viability of nucleus pulposus cells (NPCs) were measured by CCK-8 assays and EdU staining. The senescence associated secreted phenotype (SASP) factors expressions were measured by qPCR, western blot, and ELISA; and NF-κB pathway was detected by immunofluorescence and western blot. Molecular docking was applied to predict the interacting protein of QUE; while Nrf2 was knocked down by siRNAs to confirm its role in QUE regulated senescence phenotype. X-ray, MRI, Hematoxylin-Eosin and Safranin O-Fast green staining were performed to evaluate the therapeutic effects of QUE on IDD in the puncture-induced rat model. In in vitro experiments, QUE inhibited SASP factors expression and senescence phenotype in IL-1β-treated NPCs. Mechanistically, QUE suppressed IL-1β induced activation of the NF-κB pathway cascades; it was also demonstrated in molecular docking and knock down studies that QUE might bind to Keap1-Nrf2 complex to suppress NF-κB pathway. In vivo, QUE ameliorated the IDD process in the puncture-induced rat model. Together the present work suggests that QUE inhibits SASP factors expression and senescence phenotype in NPCs and ameliorates the progression of IDD via the Nrf2/NF-κB axis, which supports senolytic agent QUE as a potential therapeutic agent for the treatment of IDD.
Keywords
- Intervertebral disc degeneration
- NF-κB pathway
- Nrf2
- Quercetin
- Senescence
To clarify the regulation of astragalus on the aging BMSCs model and the effect of astragalus on Vitamin D (VD)-FGF23-Klotho axis. siRNA was used to interfere the expression of VDR gene in aging BMSCs. Serum containing astragalus in different concentrations was added to the cultured cells. The expression of osteocalcin and alkaline phosphatase were detected by alizarin red staining and ELISA. Cell vitality was detected by flow cytometry, CCK-8 test, and [i]β[/i]-galactosidase staining. The expression of FGF23, Klotho, CYP27B1, and CYP24A1 was detected by qRT-PCR and western blot. The results showed that after reducing VDR gene expression, the aging BMSCs model showed decreased activity and osteogenic ability, increased expression of FGF23, Klotho and CYP24A1, and decreased expression of CYP27B1. After adding serum-containing astragalus, the activity of cells and the osteogenic ability was increased; the expression levels of FGF23, Klotho and CYP24A1 were decreased, the expression levels of CYP27B1 were increased, and the trend was more obvious with the increase of astragalus concentration. This study confirmed that astragalus could inhibit the aging of BMSCs and improve the osteogenesis ability by regulating the VD-FGF23-Klotho pathway. This study provided a certain research basis for the therapeutic of traditional Chinese medicine (TCM) on primary osteoporosis.
Keywords
- Astragalus
- BMSCs
- VD-FGF23-Klotho axis
- aging
- osteogenesis differentiation
Protein-rich supplements are used commonly to increase energy intake in undernourished older people. This study aimed to establish age effects on energy intake, appetite, gastric emptying, blood glucose, and gut hormones in response to protein-rich drinks. In a randomized double-blind, order, 13 older men (age: 75 ± 2 yrs, body mass index (BMI): 26 ± 1 kg/m ) and 13 younger (23 ± 1 yrs, 24 ± 1 kg/m ) men consumed (i) a control drink (~2 kcal) or drinks (450 mL) containing protein/fat/carbohydrate: (ii) 70 g/0 g/0 g (280 kcal/'P ), (iii) 14 g/12.4 g/28 g (280 kcal/'M ), (iv) 70 g/12.4 g/28 g (504 kcal/'M ), on four separate days. Appetite (visual analog scales), gastric emptying (3D ultrasonography), blood glucose, plasma insulin, ghrelin, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) concentrations (0-180 min), and ad-libitum energy intake (180-210 min) were determined. Older men, compared to younger men, had higher fasting glucose and CCK concentrations and lower fasting GLP-1 concentrations (all [i]p[/i] < 0.05). Energy intake by P compared to control was less suppressed in older men (increase: 49 ± 42 kcal) than it was in younger men (suppression: 100 ± 54 kcal, [i]p[/i] = 0.038). After the caloric drinks, the suppression of hunger and the desire to eat, and the stimulation of fullness was less ([i]p[/i] < 0.05), and the stimulation of plasma GLP-1 was higher ([i]p[/i] < 0.05) in older men compared to younger men. Gastric emptying, glucose, insulin, ghrelin, and CCK responses were similar between age groups. In conclusion, ageing reduces the responses of caloric drinks on hunger, the desire to eat, fullness, and energy intake, and protein-rich nutrition supplements may be an effective strategy to increase energy intake in undernourished older people.
Keywords
- aging
- appetite
- energy intake
- gastric emptying
- glucose
- gut hormones
- whey protein
Lactose is a disaccharide found in milk and thus a part of our daily food intake. Upon ingestion, it is hydrolyzed to glucose and galactose by the enzyme lactase and absorbed in the small intestine. People who suffer from lactose intolerance are unable to completely digest it due to deficiency of lactase, leading to intestinal problems such as diarrhoea, and bloating. Various studies have focused on treating these symptoms. However, the effects of lactose that diffuses passively into cells, on cellular senescence have largely remained unknown. Thus, the present study investigated the effects and mechanisms of lactose on senescence both [i]in vitro[/i] and [i]in vivo[/i]. The study was conducted in MRC-5 cells. The cellular senescence was estimated by determining the expression of SA-β-gal and p16 . The cell viability of MRC-5 cells was determined by the CCK-8 Assay. Activity of intracellular reactive oxygen species was estimated by measuring the levels of superoxide dismutase (SOD), glutathione (GHS), and reactive oxygen species (ROS). The mechanism of lactose on cellular senescence was explored by western blotting. We also studied the effect of lactose on the lifespan of [i]Caenorhabditis elegans[/i]. Increased activities of SA-β-gal and p16 revealed the ability of lactose to induce senescence in MRC-5 cells. The elevated intracellular ROS level and decreased GSH and SOD levels in these cells were indicative of cellular oxidative stress induced by lactose. Furthermore, western blotting analysis of Nrf2 and mRNA expression of its downstream genes suggested the Nrf2/ARE pathway was involved in the oxidative stress induced by lactose. These results were further validated by the shortened lifespan of C. elegans after lactose supplement. Moreover, the lactose-induced senescence could be alleviated by an antioxidant, N-Acetyl-L-cysteine (NAC), both [i]in vitro[/i] and [i]in vivo[/i]. The present study observed a positive correlation between lactose and cellular oxidative stress, suggesting the latter to be an underlying mechanism of lactose-induced senescence.
Keywords
- Lactose
- Nrf2
- ROS
- cellular senescence
- oxidative stress
To investigate the process by which quercetin suppresses atherosclerosis by upregulating MST1-mediated autophagy in RAW264.7 macrophages. An in vitro foam cell model was established by culturing RAW264.7 macrophages with oxidized low-density lipoprotein (ox-LDL). The cells were treated with quercetin alone or in combination with the autophagy inhibitor, 3-methyladenine, and autophagy agonist, rapamycin. Cell viability was detected with a CCK-8 kit. Lipid accumulation was detected by oil red O staining, senescence was detected by SA-β-gal (senescence-associated β-galactosidase) staining, reactive oxygen species were detected by ROS assay kit. Autophagosomes and mitochondria were detected by transmission electron microscope (TEM), and expression of MST1, LC3-II/I, Beclin1, Bcl-2, P21, and P16 were detected by immunofluorescence and Western blot. Ox-LDL induced RAW264.7 macrophage-derived foam cell formation, reduced survival, aggravated cell lipid accumulation, and induced a senescence phenotype. This was accompanied by decreased formation of autophagosome; increased expression of P53, P21, and P16; and decreased expression of LC3-II/I and Beclin1. After intervention with quercetin, the cell survival rate was increased, and lipid accumulation and senescence phenotype were reduced. Furthermore, the expression of LC3-II/I and Beclin1 were increased, which was consistent with the ability of quercetin to promote autophagy. Ox-LDL also increased the expression of MST1, and this increase was blocked by quercetin, which provided a potential mechanism by which quercetin may protect foam cells against age-related detrimental effects. Quercetin can inhibit the formation of foam cells induced by ox-LDL and delay senescence. The mechanism may be related to the regulation of MST1-mediated autophagy of RAW264.7 cells.
MeSH Terms
- Adenine
- Animals
- Atherosclerosis
- Autophagy
- Cell Survival
- Cellular Senescence
- Cyclin-Dependent Kinase Inhibitor p16
- Cyclin-Dependent Kinase Inhibitor p21
- Disease Progression
- Foam Cells
- Hepatocyte Growth Factor
- Lipid Metabolism
- Lipoproteins, LDL
- Mice
- Proto-Oncogene Proteins
- Quercetin
- RAW 264.7 Cells
- Sirolimus
- Up-Regulation
Keywords
- RAW264.7
- atherosclerosis
- autophagy
- quercetin
- senescence
Long noncoding RNA (lncRNA) disorder has been found in many kinds of age-associated diseases. However, the role of lncRNA in the development of age-related hearing loss (AHL) is still largely unknown. This study sought to uncover AHL-associated lncRNAs and the function. RNA-sequencing was conducted to profile lncRNA expression in the cochlea of an early-onset AHL mouse model. RT-qPCR assay was used to validate the expression pattern of lncRNAs. ATP assay, JC-1 assay, mitochondrial probe staining, CCK-8 assay, Western blot, and immunocytochemistry were performed to detect the effects of lncRNA AW112010 in HEI-OC1 cells and the mouse cochlea. We identified 88 significantly upregulated lncRNAs and 46 significantly downregulated lncRNAs in the cochlea of aged C57BL/6 mice. We focused on the significantly upregulated AW112010. Silencing of AW112010 decreased the ATP level, mitochondrial membrane potential, and cell viability and increased mitochondrial ROS generation under oxidative stress in HEI-OC1 cells. AW112010 overexpression promoted cell survival in HEI-OC1 cells. AW112010 knockdown reduced mitochondrial mass and impaired mitochondrial biogenesis in HEI-OC1 cells. Activation of mitochondrial biogenesis by resveratrol and STR1720 promoted cell survival. The mitochondrial biogenesis process was activated in the cochlea of aged mice. Moreover, AW112010 regulated AMPK signaling in HEI-OC1 cells. Transcription factor Arid5b elevated in the aged cochlea and induced AW112010 expression and mitochondrial biogenesis in HEI-OC1 cells. Taken together, lncRNAs are dysregulated with aging in the cochlea of C57BL/6 mice. The Arid5b/AW112010 signaling was induced in the aged mouse cochlea and positively modulated the mitochondrial biogenesis to maintain mitochondrial function.
MeSH Terms
- Adenosine Triphosphate
- Aging
- Animals
- Cell Survival
- DNA-Binding Proteins
- Gene Silencing
- Hair Cells, Auditory
- Hearing Loss
- Mice
- Mitochondria
- Organelle Biogenesis
- RNA, Long Noncoding
- Resveratrol
- Signal Transduction
- Transcription Factors
Older people are likely to develop anorexia of aging. Rostral C1 (rC1) catecholaminergic neurons in rostral ventrolateral medulla (RVLM) are recently discovered its role in food intake control. It is well established that these neurons regulate cardiovascular function. This study aims to determine the effect of age on the function of rostral C1 (rC1) neurons in mediating feeding response. Male Sprague Dawley rats at 3-months (n = 22) and 24-months (n = 22) old were used and further divided into two subgroups; 1) treatment group with 2-deoxy-d-glucose (2DG) and 2) vehicle group. Feeding hormones such as cholecystokinin (CCK), ghrelin and leptin were analysed using enzyme-linked immunosorbent assay (ELISA). Rat brain was carefully dissected to obtain the brainstem RVLM region. Further analysis was carried out to determine the level of proteins and genes in RVLM that were associated with feeding pathway. Protein expression of tyrosine hydroxylase (TH), phosphorylated TH at Serine40 (pSer40TH), AMP-activated protein kinase (AMPK), phosphorylated AMPK (phospho AMPK) and neuropeptide Y Y5 receptor ([[NPY5R]]) were determined by western blot. Expression of TH, AMPK and NPY genes were determined by real-time PCR. This study showed that blood glucose level was elevated in young and old rats following 2DG administration. Plasma CCK-8 concentration was higher in the aged rats at basal and increased with 2DG administration in young rats, but the leptin and ghrelin showed no changes. Old rats showed higher TH and lower AMPK mRNA levels. Glucoprivation decreased AMPK mRNA level in young rats and decreased TH mRNA in old rats. Aged rC1 neurons showed higher [[NPY5R]] protein level. Following glucoprivation, rC1 neurons produced distinct molecular changes across age in which, in young rats, AMPK phosphorylation level was increased and in old rats, TH phosphorylation level was increased. These findings suggest that glucose-counterregulatory responses by rC1 neurons at least, contribute to the ability of young and old rats in coping glucoprivation. Age-induced molecular changes within rC1 neurons may attenuate the glucoprivic responses. This situation may explain the impairment of feeding response in the elderly.
Keywords
- Aging
- Catecholaminergic neurons
- Feeding response
- Glucoprivation
- Rostral ventrolateral medulla
To understand the changes in physiological responses due to aging, a number of bioactive probes based on different signal transduction pathways are necessary. In this study, we comprehensively and systematically investigated changes in blood vessel function with age using a 336-dipeptide library. In the early stage of hypertension, the most potent vasorelaxant dipeptide was Ser-Tyr (SY) in the mesenteric artery isolated from spontaneously hypertensive rats (SHR). SY-induced vasorelaxation and anti-hypertensive effects were blocked by L-NAME, an inhibitor of nitric oxide synthase (NOS), suggesting that SY activates the NO system. On the other hand, the patterns of dipeptides with vasorelaxation activity in early and advanced stages of hypertension were different. In the advanced stage, the most potent vasorelaxing dipeptide was Asn-Ala (NA). Orally administered NA (1.5 mg/kg) reduced the blood pressure in the advanced stage, at which drugs were sometimes less effective, and the anti-hypertensive effects lasted for 6 hr. The NA-induced vasorelaxation and anti-hypertensive activity was blocked by lorglumide, an antagonist of the cholecystokinin CCK receptor, suggesting that NA activated the CCK system. Taken together, in the early and advanced stages of hypertension, SY and NA exhibited vasorelaxing and anti-hypertensive effects via the NO and CCK systems, respectively.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Antihypertensive Agents
- Blood Pressure
- Cholecystokinin
- Dipeptides
- Drug Evaluation, Preclinical
- Hypertension
- Male
- Mesenteric Arteries
- Nitric Oxide
- Peptide Library
- Proglumide
- Rats
- Rats, Inbred SHR
- Receptors, Cholecystokinin
- Vasodilation
- Vasodilator Agents
Keywords
- aging
- dipeptide library
- nitric oxide
- structure-activity relationship
- vasorelaxation
To test the hypothesis that the flavonoid compound, fisetin, protects macrophages from lipid accumulation and senescence through regulation of casein kinase 2-interacting protein-1 (CKIP-1)/REGγ (11S regulatory particles, 28 kDa proteasome activator, proteasome activator subunit 3) signaling. RAW264.7 macrophage cells were exposed to 100 μg/ml oxidized low-density lipoprotein (ox-LDL) with or without 20 μg/ml fisetin for 24 h. Cell viability was detected by CCK-8 after 1 h. Intracellular lipid accumulation was measured using Oil Red O staining. Total cholesterol (TC) and free cholesterol (FC) contents were measured using assay kits, and cell senescence was inferred by β-gal staining. Protein expression levels of CKIP-1, REGγ, organic cation transporter 1 (Oct-1), lectin-like oxidized LDL receptor-1 (LOX-1), tumor suppressor protein p53 (p53), cell cycle regulatory protein p21 (p21), and multiple tumor suppressor-1 (p16) were detected by immunofluorescence and confirmed by Western blot. Stimulating RAW264.7 macrophage cells with 100 μg/ml ox-LDL for 24 h induced the formation of foam cells, increased intracellular lipid accumulation, increased TC and FC content, and promoted cell senescence. Furthermore, cells induced with 100 μg/ml ox-LDL for 24 h showed decreased CKIP-1 and REGγ protein, while the expressions of Oct-1, LOX-1, p53, p21 and p16 were increased. In contrast, treatment with 20 μg/ml fisetin reversed 100 μg/ml ox-LDL effects to increase cell viability, and decrease β-gal staining, intracellular lipid levels and TC and FC levels. These beneficial effects were associated with increased CKIP-1 and REGγ and decreased Oct-1, LOX-1, p53, p21, and p16 protein expression. Results indicated that fisetin limited ox-LDL-mediated lipid accumulation and senescence in RAW264.7 macrophage-derived foam cells. The mechanism underlying these effects may involve regulation of CKIP-1/REGγ signaling.
MeSH Terms
- Animals
- Autoantigens
- Carrier Proteins
- Cellular Senescence
- Flavonoids
- Foam Cells
- Lipid Metabolism
- Lipoproteins, LDL
- Mice
- Proteasome Endopeptidase Complex
- RAW 264.7 Cells
- Signal Transduction
Keywords
- CKIP-1/REGγ signaling
- Fisetin
- Lipid accumulation
- RAW264.7
- Senescence
The aim of this paper was to investigate the effect of SIRT1/TSC_2 signal axis on leukemia stem cell senescence induced by ginsenoside Rg_1. CD34~ CD38~- leukemia stem cells(CD34~ CD38~-LSCs) was isolated by magnetic cell sorting(MACS) and divided into two groups. The control group cells were routinely cultured, 40 μmol·L~(-1) ginsenoside Rg_1 was added to the control group for co-culture in Rg_1 group. The effect of Rg_l to induce CD34~ CD38~-LSCs senescence were evaluated by senescence-associated β-Galactosidase(SA-β-Gal) staining, cell cycle assay, CCK-8 and Colony-Assay. The expression of senescence associated SIRT1, TSC_2 mRNA and protein was examined by Real-time fluorescence quantitative PCR(FQ-PCR) and Western blot. The results showed that the CD34~ CD38~-LSCs could effectively be isolated by MACS, and the purity of CD34~ CD38~-LSCs is up to(95.86±3.04)%. Compared with the control group, the percentage of positive cells expressed SA-β-Gal in the Rg_1 group is increased, the senescence morphological changes were observed in the CD34~ CD38~-LSCs in the Rg_1 group. The proliferation inhibition rate and the number of cells entered G_0/G_1 phase in the Rg_1 group were increased, but the colony-formed ability was decreased, Rg_1 could significantly inhibit the proliferation and self-renewal ability of CD34~ CD38~-LSCs. The expression of SIRT1 and TSC_2 mRNA and protein were down regulated in the Rg_1 group compared with the control group. Our research implied that Rg_1 may induce the senescence of CD34~ CD38~-LSCs and SIRT1/TSC_2 signal axis plays a significant role in this process.
MeSH Terms
- Cellular Senescence
- Ginsenosides
- Humans
- Leukemia, Myeloid, Acute
- Neoplastic Stem Cells
- Signal Transduction
- Sirtuin 1
- Tuberous Sclerosis Complex 2 Protein
- Tumor Cells, Cultured
Keywords
- CD34~ CD38~-LSCs
- SIRT1
- TSC_2
- ginsenoside Rg_1
- senescence
Cellular senescence is a well-known cancer prevention mechanism, inducing cancer cells to senescence can enhance cancer immunotherapy. However, how cellular senescence is regulated is not fully understood. Dynamic chromatin changes have been discovered during cellular senescence, while the causality remains elusive. BAZ1A, a gene coding the accessory subunit of ATP-dependent chromatin remodeling complex, showed decreased expression in multiple cellular senescence models. We aim to investigate the functional role of BAZ1A in regulating senescence in cancer and normal cells. Knockdown of BAZ1A was performed via lentivirus mediated short hairpin RNA (shRNA) in various cancer cell lines (A549 and U2OS) and normal cells (HUVEC, NIH3T3 and MEF). A series of senescence-associated phenotypes were quantified by CCK-8 assay, SA-β-Gal staining and EdU incorporation assay, etc. KEY FINDINGS: Knockdown (KD) of BAZ1A induced series of senescence-associated phenotypes in both cancer and normal cells. BAZ1A-KD caused the upregulated expression of SMAD3, which in turn activated the transcription of p21 coding gene CDKN1A and resulted in senescence-associated phenotypes in human cancer cells (A549 and U2OS). Our results revealed chromatin remodeling modulator BAZ1A acting as a novel regulator of cellular senescence in both normal and cancer cells, indicating a new target for potential cancer treatment.
MeSH Terms
- A549 Cells
- Animals
- Bone Neoplasms
- Cells, Cultured
- Cellular Senescence
- Chromatin Assembly and Disassembly
- Chromosomal Proteins, Non-Histone
- Fibroblasts
- Human Umbilical Vein Endothelial Cells
- Humans
- Mice
- NIH 3T3 Cells
- Osteosarcoma
- Signal Transduction
- Transcription Factors
Keywords
- BAZ1A
- Chromatin remodeling factor
- SMAD3
- Senescence
Circular RNA (circRNA) is a class of noncoding RNA that regulates the activity of microRNAs and gene expression. Altered circRNA expression is associated with human diseases. The present study profiled differentially expressed circRNAs in the ultraviolet B stress-induced human fibroblast premature senescence (UVB-SIPS) model, and assessed the role of circRNA_100797 in UVB-SIPS. The UVB-SIPS model was confirmed by ß-galactosidase staining, cell viability CCK-8 assay, and flow cytometric cell cycle distribution assay, and subjected to circRNA gene chip profiling. These differentially expressed circRNAs were analyzed using the clusterProfiler R package for Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathways. The selected circRNAs were confirmed using quantitative reverse transcription polymerase chain reaction (qRT-PCR), the relationship of circRNA_100797 with miR-23a-5p was assessed using luciferase reporter assay, and their functions were determined by qRT-PCR and western blot analysis. A total of 472 differentially expressed circRNAs occurred in the UVB-SIPS. qRT-PCR confirmed five of eight differentially expressed circRNAs. The GO and KEGG analyses revealed that these differently expressed circRNAs function in biology process, cell component, and molecular function. Furthermore, it was found that circRNA_100797 had a low expression in UVB-SIPS. However, when circRNA_100797 was overexpressed, the acceleration of cell proliferation and alleviation of cell cycle arrest were observed. Moreover, circRNA_100797 could target miR-23a-5p, their expression levels were inversely associated in fibroblasts, and the miR-23a-5p overexpression blocked the effect of the overexpression of circRNA_100797 in UVB-SIPS. The present study demonstrated that circRNA_100797 acts as a sponge of miR-23a-5p, and has a photoprotection role in UVB-irradiated fibroblasts.
MeSH Terms
- Adolescent
- Adult
- Cell Cycle Checkpoints
- Cell Proliferation
- Cells, Cultured
- Cellular Senescence
- Fibroblasts
- Gene Expression Profiling
- Gene Regulatory Networks
- Humans
- Male
- MicroRNAs
- Oligonucleotide Array Sequence Analysis
- RNA, Circular
- Time Factors
- Transcriptome
- Ultraviolet Rays
- Young Adult
Keywords
- cell senescence
- circRNA_100797
- circular RNA
- miR-23a-5p
- microarray
Long non-coding RNA-oncogene-induced senescence 1 (lncRNA-OIS1) is a novel lncRNA that is involved in oncogene-induced senescence, while its functionality in cervical squamous cell carcinoma is unknown. In the present study, 68 human papillomavirus (HPV)-positive and 22 HPV-negative patients with cervical squamous cell carcinoma were recruited. Additionally, 40 healthy females were employed as healthy controls. Tumor tissues and adjacent healthy tissues were collected from all patients with cervical squamous cell carcinoma, and blood samples were obtained. Expression of OIS1 was detected by reverse transcription-quantitative polymerase chain reaction. Receiver operating characteristic curve analysis was used to evaluate the diagnostic value of OIS1 for cervical squamous cell carcinoma. HPV-positive and HPV-negative cervical squamous cell carcinoma and normal cervical cell lines were used, and the effects of OIS1 or mitogen-activated protein kinase kinase kinase 4, (MTK-1) expression vector transfection on the proliferation of cell lines and MTK-1 expression were detected by CCK-8 assay and western blotting, respectively. It was established that a reduction in OIS1 expression level in tumor tissues was apparent only in HPV-positive patients. Serum levels of OIS1 were lower in HPV-positive patients compared with that in HPV-negative patients and healthy controls, and no significant differences were observed between HPV-negative patients and healthy controls. Serum levels of OIS1 were significantly associated with tumor size, but not distant tumor metastasis. OIS1 expression level was lower in HPV-positive cancer cell lines compared with that in HPV-negative cancer cell lines, while no significant differences were observed between HPV-positive and HPV-negative normal cell lines. OIS1 overexpression inhibited and MTK-1 overexpression promoted the proliferation of HPV-positive, but not HPV-negative cancer or normal cell lines. OIS1 transfection also decreased the expression of MTK-1 in HPV-positive cancer cell lines, but not in any of the other cell lines. Therefore, it was concluded that OIS1 inhibited HPV-positive, but not HPV-negative cervical squamous cell carcinoma by upregulating MTK-1.
Keywords
- cervical squamous cell carcinoma
- human papilloma virus
- long non-coding RNA-oncogene-induced senescence 1
- mitogen-activated protein kinase kinase kinase 4
Ubiquinol-cytochrome C reductase core protein II (QCR2) is essential for mitochondrial functions, yet, its role in cancer development has remained elusive. The expression of QCR2 in cancer patients was assessed by immunohistochemistry. The proliferation of cancer cells was assessed by CCK-8 assay, EdU staining and Flow cytometry analysis. The biological function of QCR2 and PHB were determined using western blotting, RT-qPCR, microarray analysis and xenografts. The interactions between proteins and the ubiquitination of p53 were assessed by immunoprecipitation, mass spectrometry analysis and GST pull down. The subcellular location of PHB and QCR2 was assessed by immunoblotting and immunofluorescence. The expression of QCR2 is upregulated in multiple human tumors. Suppression of QCR2 inhibits cancer cell growth by activating p53 signaling and inducing p21-dependent cell cycle arrest and senescence. QCR2 directly interacts with PHB in the mitochondria. Overexpression of QCR2 inhibits PHB binding to p53 in the nucleus, and facilitates p53 ubiquitination and degradation, consequently leading to tumorigenesis. Also, increased QCR2 and decreased PHB protein levels are well correlated with decreased expression of p21 in cervical cancer tissues. These results identify a novel role for QCR2, together with PHB, in negative regulation of p53 stability and activity, thus promote cervical carcinogenesis. FUND: "973" Program of China, the National Science-technology Supporting Plan Projects, the National Natural Science Foundation of China, National Science and Technology Major Sub-Project and Technical Innovation Special Project of Hubei Province.
MeSH Terms
- Animals
- Cell Cycle Checkpoints
- Cell Line, Tumor
- Cell Proliferation
- Cell Transformation, Neoplastic
- Cellular Senescence
- Electron Transport Complex III
- Female
- Gene Expression
- Gene Knockdown Techniques
- Gene Silencing
- Humans
- Immunohistochemistry
- Mice
- Models, Biological
- Neoplasms
- Protein Binding
- Proteolysis
- Tumor Suppressor Protein p53
- Ubiquitination
Keywords
- Degradation
- PHB
- QCR2
- Senescence
- Tumorigenesis
- p53
Osteoarthritis (OA) is the prevalent degenerative disease caused by various factors. MicroRNAs are important regulators in the inflammation and immune response. The aim of this study was to investigate the effect of microRNA-34a (MiR-34a) on the death of chondrocytes, senescence, as well as its role in OA progression. A series of experiments involving CCK-8, flow cytometry, β-galactosidase staining and wound healing assays were conducted to determine the cellular capabilities of proliferation, cell apoptosis, senescence and the ability of cells to recover from injury, respectively. Binding sites between miR-34a and delta-like protein 1 (DLL1) were identified using a luciferase reporter system, whereas mRNA and protein expression of target genes was determined by RT-PCR and immunoblot, respectively. OA model was generated via surgery. We found that miR-34a expression was increased in the cartilage of OA patients. In rat chondrocytes and chondrosarcoma cells, miR-34a transfections noticeably inhibited the expression of DLL1, triggered cell death and senescence, suppressed proliferation, and prevented scratch assay wound closure. However, transfection of a miR-34a inhibitor displayed adverse effects. Additionally, secretion and expression of factors associated with cartilage degeneration were altered via miR-34a. Moreover, miR-34a directly inhibits DLL1 mRNA. Furthermore, concentrations of DLL1, total PI3K, and p-AKT declined in chondrocytes that overexpress miR-34a. DLL1 overexpression elevated PI3K and p-AKT levels, and eliminated cell death triggered by a miR-34a mimic. In vivo, miR-34a remarkably inhibited miR-34a up-regulation, while enhanced the level of DLL1 expression. In the knee joints of surgery-induced OA rats, articular chondrocyte death and loss of cartilage were attenuated via miR-34a antagomir injection. These findings indicate that miR-34a contributes to chondrocyte death, causing OA progression through DLL1 and modulation of the PI3K/AKT pathway.
MeSH Terms
- Aged
- Animals
- Apoptosis
- Calcium-Binding Proteins
- Cells, Cultured
- Cellular Senescence
- Chondrocytes
- Down-Regulation
- Female
- Humans
- Intercellular Signaling Peptides and Proteins
- Male
- Membrane Proteins
- MicroRNAs
- Middle Aged
- Osteoarthritis
- Phosphatidylinositol 3-Kinases
- Proto-Oncogene Proteins c-akt
- Rats
- Rats, Sprague-Dawley
- Signal Transduction
Keywords
- Apoptosis
- DLL1
- Mir-34a
- OA
- PI3K-AKT
- Senescence
Flavokawain B (FKB), a natural kava chalcone, displays potent antitumor activity in various types of cancer. The mechanism of action, however, remains unclear. Here, we evaluated the efficacy of FKB in the treatment of human glioblastoma multiforme (GBM) as well as the molecular basis for its inhibitory effects in cancer. Approximately 60% of GBM cells became senescent after treatment with FKB as assessed in the senescence-associated (SA)-GLB1/SA-β-galactosidase assay. The cellular process of autophagy potentially contributed to the establishment of senescence. Transmission electron microscopy revealed the formation of autophagic vesicles under FKB treatment, and MAP1LC3B (microtubule associated protein 1 light chain 3 beta)-II was increased. Transfection of ATG5 or ATG7 small interfering RNAs (siRNAs) inhibited FKB-induced autophagy in U251 cells. Western blot revealed that molecular components of the endoplasmic reticulum stress pathway were activated, including ATF4 (activating transcription factor 4) and [[DDIT3]] (DNA damage inducible transcript 3), while levels of TRIB3 (tribbles pseudokinase 3) increased. In addition, based on the phosphorylation status, the AKT-MTOR-RPS6KB1 pathway was inhibited, which induced autophagy in GBM cells. Inhibition of autophagy by autophagy inhibitors 3-methyladenine and chloroquine or knockdown of ATG5 or ATG7 caused FKB-treated U251 cells to switch from senescence to apoptosis. Finally, knockdown of ATG5 or treatment with chloroquine in combination with FKB, significantly inhibited tumor growth in vivo. Our results demonstrated that FKB induced protective autophagy through the ATF4-[[DDIT3]]-TRIB3-AKT-MTOR-RPS6KB1 signaling pathway in GBM cells, indicating that the combination treatment of FKB with autophagy inhibitors may potentially be an effective therapeutic strategy for GBM. 3-MA: 3-methyladenine; 4-PBA: 4-phenylbutyrate; AKT: AKT serine/threonine kinase; ATF4: activating transcription factor 4; ATG: autophagy related; CASP3: caspase 3; CCK-8: cell counting kit-8; CDKN1A: cyclin-dependent kinase inhibitor 1A; CQ: chloroquine; [[DDIT3]]: DNA damage inducible transcript 3; DMEM: Dulbecco's modified Eagle's medium; EIF2A: eukaryotic translation initiation factor 2A; EIF2AK3: eukaryotic translation initiation factor 2 alpha kinase 3; ER: endoplasmic reticulum; FKB: flavokawain B; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; GBM: glioblastoma multiforme; GFP: green fluorescent protein; HSPA5: heat shock protein family A (Hsp70) member 5; MAP1LC3B: microtubule associated protein 1 light chain 3 beta; MTOR: mechanistic target of rapamycin kinase; PARP1: poly(ADP-ribose) polymerase; 1RPS6KB1: ribosomal protein S6 kinase B1; SA-GLB1: senescence-associated galactosidase beta 1; siRNA: short interfering RNA; SQSTM1: sequestosome 1; TEM: transmission electron microscopy; TRIB3: tribbles pseudokinase 3; TUNEL: deoxynucleotidyl transferase-mediated dUTP nick-end labeling.
MeSH Terms
- Animals
- Antineoplastic Agents, Phytogenic
- Autophagy
- Autophagy-Related Protein 5
- Autophagy-Related Protein 7
- Cell Proliferation
- Cells, Cultured
- Endoplasmic Reticulum Stress
- Flavonoids
- Gene Expression Regulation, Neoplastic
- Glioma
- Humans
- Male
- Mice
- Mice, Nude
- Xenograft Model Antitumor Assays
Keywords
- Apoptosis
- ER stress
- autophagy
- flavokawain B
- senescence
Previous studies have shown that endothelial cell senescence is involved in cardiovascular diseases such as cardiac fibrosis, atherosclerosis and heart failure. Accumulating evidence indicates that apelin exerts protective effects on ageing-related endothelial dysfunction. In this study, we aim to investigate the role of the apelin/APJ axis in angiotensin II (AngII)-induced endothelium senescence and its associated mechanisms. Senescence-related β-gal activity assay and western blot were used to evaluate human umbilical vein endothelial cell (HUVEC) senescence. In addition, DCFH-DA staining was carried out to detect the generation of reactive oxygen species (ROS). A validated, high-sensitivity real-time quantitative telomeric repeat amplification protocol (RQ-TRAP) was applied to determine telomerase activity in HUVECs, and a CCK-8 assay was employed to measure cellular viability. AngII induced an increase in SA-β-Gal-positive cells and upregulation on expression of P21 and PAI-1 compared to the control group ([i]p[/i] < 0.05), while apelin against this process ([i]p[/i] < 0.05). The protective effects were attenuated when APJ, AMPK and SIRT1 expression was knocked down ([i]p[/i] < 0.05). Furthermore, apelin reduced AngII-induced ROS generation and enhanced telomerase activity in HUVECs ([i]p[/i] < 0.05), which contributed to increased HUVEC viability as assessed by the CCK-8 assay ([i]p[/i] < 0.05). The apelin/APJ axis improved AngII-induced HUVEC senescence via the AMPK/SIRT1 signaling pathway, and the underlying mechanisms might be associated with reduced ROS production and enhanced telomerase activity.
Keywords
- apelin
- endothelium
- mechanisms
- senescence
In our previous study, we found that osthole could promote the ability of proliferation and differentiation in normal neural stem cells (NSCs) under normal condition. Then, we used tert-butyl hydroperoxide (t-BHP) to establish the model of senescence NSCs to detect the effects of osthole. Interestingly, the immunofluorescence results showed that osthole (100 μM) could enhance the ability of proliferation and differentiation, and CCK-8 assay results showed that osthole could also enhance the cell viabilities. Then, SA-β-gal assay results showed that osthole could decrease the positive of senescence cells. Flow cytometric analysis results showed that osthole could decrease the mixture of G0 and G1 phase. Reverse transcriptase (RT)-polymerase chain reaction results showed that osthole could downregulate the expression of p16 mRNA, and western blot analysis results showed that the expressions of the target protein decreased in p16-pRb signaling pathway with osthole treatment. In conclusion, these results indicated that osthole could probably delay cells senescence through p16-pRb signaling pathway.
MeSH Terms
- Animals
- Animals, Newborn
- Calcium Channel Blockers
- Cell Cycle
- Cells, Cultured
- Cellular Senescence
- Coumarins
- Mice
- Neural Stem Cells
- Signal Transduction
- tert-Butylhydroperoxide
Keywords
- aging
- neural stem cells
- osthole
- p16
- tert-butyl hydroperoxide
Diabetes mellitus (DM) is a potential etiology of disc degeneration. N-cadherin (N-CDH) helps maintain the cell viability, cell phenotype and matrix biosynthesis of nucleus pulposus (NP) cells. Here, we mainly aimed to investigate whether N-CDH can attenuate high glucose-induced NP cell senescence and its potential mechanism. Rat NP cells were cultured in a base culture medium and base culture medium with a 0.2 M glucose concentration. Recombinant lentiviral vectors were used to enhance N-CDH expression in NP cells. Senescence-associated β-galactosidase (SA-β-Gal) activity was measured by SA-β-Gal staining. NP cell proliferation was evaluated by CCK-8 assay. Telomerase activity and intracellular reactive oxygen species (ROS) content were tested by specific chemical kits according to the manufacturer's instructions. G0/G1 cell cycle arrest was evaluated by flow cytometry. Real-time PCR and Western blotting were used to analyze mRNA and protein expressions of senescence markers (p16 and p53) and matrix macromolecules (aggrecan and collagen II). Additionally, p-NF-κB expression was also analyzed by Western blotting to evaluate NF-κB pathway activity. High glucose significantly decreased N-CDH expression, increased ROS generation and NF-κB pathway activity, and promoted NP cell senescence, which was reflected in the increase in SA-β-Gal activity and senescence marker (p16 and p53) expression, compared to the control group. High glucose decreased telomerase activity and cell proliferation potency. However, N-CDH overexpression partially attenuated NP cell senescence, decreased ROS content and inhibited the activation of the NF-κB pathway under the high glucose condition. High glucose decreases N-CDH expression and promotes NP cell senescence. N-CDH overexpression can attenuate high glucose-induced NP cell senescence through the regulation of the ROS/ NF-κB pathway. This study suggests that N-CDH is a potential therapeutic target to slow DM-mediated disc NP degeneration.
MeSH Terms
- Animals
- Cadherins
- Cells, Cultured
- Cellular Senescence
- Diabetes Mellitus
- NF-kappa B
- Nucleus Pulposus
- Rats
- Reactive Oxygen Species
- Signal Transduction
Keywords
- Cell senescence
- Diabetes mellitus
- Glucose
- NF-κB
- Nucleus pulposus
- Reactive oxygen species
The peptide hormone cholecistokinin (CCK) plays a key role in the central and peripheral nervous system. It is known to be involved in the digestive physiology and in the regulation of food intake. Moreover, the CCK expression has also been detected in the retina of different vertebrates, including fish, although its biological activity in this tissue remains to be elucidated. In literature no data are yet available about the CCK-immunoreactivity in the zebrafish retina during development. Therefore, the aim of the study was to investigate the distribution of sulfated cholecystokinin octapeptide (CCK8-S) as a well preserved form during evolution in the zebrafish retina from 3days post hatching (dph) until adult stage, using immunohistochemistry in order to elucidate the potential role of this protein in the development and maintenance of normal retinal homeostasis. The cellular distribution of CCK in the retina was similar from 3 dph to 40days post fertilization (dpf) when immunoreactivity was found in the photoreceptors layer, in the outer plexiform layer, in the inner plexiform layer and, to a lesser extent, in the ganglion cell layer (GCL). Immunohistochemical localization at 50 dpf as well as in the adult stage was observed in a subpopulation of amacrine cells in the proximal inner nuclear layer, in the inner plexiform layer, in displaced amacrine cells and in retinal ganglion cells in the GCL. Our results demonstrate for the first time the occurrence of CCK in the zebrafish retina from larval to adult stage with a different pattern of distribution, suggesting different roles of CCK during retinal cells maturation.
MeSH Terms
- Aging
- Amacrine Cells
- Animals
- Cholecystokinin
- Gene Expression Regulation, Developmental
- Immunohistochemistry
- Larva
- Microscopy, Electron, Scanning
- Photoreceptor Cells, Vertebrate
- Retina
- Retinal Ganglion Cells
- Sincalide
- Zebrafish
Keywords
- CCK8-S
- Development
- Retina
- Zebrafish
Compared to younger individuals, older human subjects have significantly lower food intakes and an increased satiety response. N-methyl-d-aspartate (NMDA) receptors expressed by vagal afferent neurons originating from nodose ganglia (NG) are involved in modulating the satiety response. The present study investigated how NMDA receptor subunit phenotypes in NG neurons change with age and how these age-related alterations in food intake are modulated by presynaptic NMDA receptors in the NG of male Sprague Dawley rats (six week-old and sixty week-old). Food intake was measured at 30-, 60-, and 120-min following intraperitoneal administration of cholecystokinin (CCK) or the non-competitive NMDA receptor antagonist MK-801. Immunofluorescence was used to determine NMDA receptor subunit expression (NR1, NR2B, NR2C, and NR2D) in the NG. The results showed that, CCK reduced food intake at 30-, 60-, and 120-min post injection in both young and the middle-age animals, with no statistical difference between the groups at 30- and 60-min. In contrast, MK-801 produced an increase in food intake that was significantly higher in middle-age rats compared to young animals at all time points studied. NR1 subunit was expressed by almost all NG neurons in both age groups. In young rats, NR2B, NR2C, and NR2D subunits were expressed in 56.1%, 49.3%, and 13.9% of NG neurons, respectively. In contrast, only 30.3% of the neuronal population in middle-aged rats expressed NR2B subunit immunoreactivity, NR2C was present in 34.1%, and only 10.6% of total neurons expressed the NR2D subunit. In conclusion, glutamate-dependent regulation of food intake is altered with age and one of the potential mechanisms through which this age-related changes in intake occur is changes in NMDA receptor phenotypes on vagal afferent neurons located in NG.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Dizocilpine Maleate
- Eating
- Male
- Neurons, Afferent
- Nodose Ganglion
- Phenotype
- Protein Subunits
- Rats
- Receptors, N-Methyl-D-Aspartate
- Satiety Response
Keywords
- Aging
- Food intake
- NMDA receptor
- Nodose ganglia
- Vagus nerve
Protein-rich supplements are used widely for the management of malnutrition in the elderly. We reported previously that the suppression of energy intake by whey protein is less in older than younger adults. The aim was to determine the effects of substitution, and adding of carbohydrate and fat to whey protein, on ad libitum energy intake from a buffet meal (180-210 min), gastric emptying (3D-ultrasonography), plasma gut hormone concentrations (0-180 min) and appetite (visual analogue scales), in healthy older men. In a randomized, double-blind order, 13 older men (75 ± 2 years) ingested drinks (~450 mL) containing: (i) 70 g whey protein (280 kcal; 'P '); (ii) 14 g protein, 28 g carbohydrate, 12.4 g fat (280 kcal; 'M '); (iii) 70 g protein, 28 g carbohydrate, 12.4 g fat (504 kcal; 'M '); or (iv) control (~2 kcal). The caloric drinks, compared to a control, did not suppress appetite or energy intake; there was an increase in total energy intake (drink meal, [i]p[/i] < 0.05), which was increased most by the M -drink. P - and M -drink ingestion were associated with slower a gastric-emptying time ([i]n[/i] = 9), lower ghrelin, and higher cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) than M ([i]p[/i] < 0.05). Glucose and insulin were increased most by the mixed-macronutrient drinks ([i]p[/i] < 0.05). In conclusion, energy intake was not suppressed, compared to a control, and particularly whey protein, affected gastric emptying and gut hormone responses.
MeSH Terms
- Aged
- Appetite
- Blood Glucose
- Cholecystokinin
- Cross-Over Studies
- Dietary Carbohydrates
- Dietary Fats
- Double-Blind Method
- Energy Intake
- Gastric Emptying
- Ghrelin
- Glucagon-Like Peptide 1
- Humans
- Insulin
- Male
- Whey Proteins
Keywords
- aging
- energy intake
- gastric emptying
- gut hormones
- whey protein
Protein-rich supplements are used widely to prevent and manage undernutrition in older people. We have previously shown that healthy older, compared to younger, adults have less suppression of energy intake by whey protein-although the effects of age on appetite-related gut hormones are largely unknown. The aim of this study was to determine and compare the acute effects of whey protein loads on blood glucose and plasma gut hormone concentrations in older and younger adults. Sixteen healthy older (eight men, eight women; mean ± SEM: age: 72 ± 1 years; body mass index: 25 ± 1 kg/m²) and 16 younger (eight men, eight women; 24 ± 1 years; 23 ± 0.4 kg/m²) adults were studied on three occasions in which they ingested 30 g (120 kcal) or 70 g (280 kcal) whey protein, or a flavored-water control drink (~2 kcal). At regular intervals over 180 min, blood glucose and plasma insulin, glucagon, ghrelin, cholecystokinin (CCK), gastric inhibitory peptide (GIP), and glucagon-like peptide-1 (GLP-1) concentrations were measured. Plasma ghrelin was dose-dependently suppressed and insulin, glucagon, CCK, GIP, and GLP-1 concentrations were dose-dependently increased by the whey protein ingestion, while blood glucose concentrations were comparable during all study days. The stimulation of plasma CCK and GIP concentrations was greater in older than younger adults. In conclusion, orally ingested whey protein resulted in load-dependent gut hormone responses, which were greater for plasma CCK and GIP in older compared to younger adults.
MeSH Terms
- Administration, Oral
- Adult
- Age Factors
- Aged
- Aging
- Beverages
- Blood Glucose
- Cholecystokinin
- Cross-Over Studies
- Dietary Supplements
- Dose-Response Relationship, Drug
- Double-Blind Method
- Female
- Gastric Inhibitory Polypeptide
- Ghrelin
- Glucagon
- Glucagon-Like Peptide 1
- Humans
- Insulin
- Male
- South Australia
- Time Factors
- Whey Proteins
- Young Adult
Keywords
- age-effect
- gut hormones
- whey protein
Background: Triptolide is a medicinal herb-derived diterpene triepoxide with potent anti-tumor activity, mainly ,correlated with its ability to inhibit and inactivate subunits of RNA polymerase II, thereby suppressing global gene transcription. Epigenetic imbalance including histone methylation are well known to play important roles in prostate cancer (PCa) onset and progression. The goal of this study was to investigate whether triptolide might exert anti-PCa influence by reshaping the histone methylation landscape. Methods: Triptolide-treated PCa cell lines were analyzed by RT-qPCR and western blotting for expression of histone demethylases and associated markers. Detection of senescence was achieved using senescence associated β-galactosidase staining and analyses of apoptosis and cell cycle were performed by flow cytometry. Senescence–associated heterochromatin foci were detected by immunofluorescence while chromatin immunoprecipitation associated with qPCR (CHIP-qPCR) was applied to assess accumulation of histone markers on promoters of target genes. Cell viability was determined using the CCK-8 assay. Results: We found triptolide to enhance H3K27me3 levels by down-regulating JMJD3 and UTX and also H3K9me3 through up-regulation of SUV39H1. Furthermore, it up-regulated expression of HP1α. Thereby, heterochromatin formation and deposition on promoters of E2F1-target genes was promoted, correlating with suppression of gene transcription, decreased cell viability and induction of a senescence-like phenotype in PCa cells. Conclusions: Our results indicate that triptolide exerts anti-tumor effects including PCa cell senescence at least partially through increasing the levels of repressive histone H3 methylation and formation of a repressive chromatin state in PCa cells. Further studies of its potential as an epigenetic anti-PCa drug appear warranted.
Keywords
- Triptolide
- prostate cancer
- senescence
- Histone
- Methylation
- Heterochromatin
To observe the effect of extracts of ginseng, notoginseng, and Chuanxiong Rhizome on the cytoskeleton protein F-actin and G-actin of the replicative senescence vascular smooth muscle cells, with human aortic smooth muscle cells (HASMC) as the research object, and the replicative senescence 9th generation cells as the senescence models, the experiment was divided into youth group (5th generation cells), model group (9th generation cells), Chinese medicine low dose group (100 mg•L⁻¹), middle dose group (200 mg•L⁻¹), and high dose group (400 mg•L⁻¹) and resveratrol group (10 μmol•L⁻¹). The intervention time was 48 h. β-Galactosidase specific staining method was used to calculate the ratio of blue dyeing cells. CCK-8 method was used to detect the cells proliferation. The flow cytometry was used to analyze the cell cycle. Immunofluorescent staining was used to observe morphological changes of F-actin and G-actin. The western blot assay was used to determine the expression of F-actin protein. Compared with the model group, the Chinese medicine groups and resveratrol group significantly reduced the number of blue dyeing cells, improved the ability of cells proliferation, reduced the number of cells in G0/G1 phase, increased the number of cells in S phase, and reduced the protein expression of F-actin and the formation of stress fibers, with obvious intervention effect and statistically significant difference. Therefore, the replicative senescence vascular smooth muscle cells can be used as the models for senescence research, with significant changes in morphology and protein expression of cytoskeleton protein F-actin and G-actin in the process of cells aging. The extracts of ginseng, notoginseng, and Chuanxiong Rhizome have obvious intervention effect on F-actin and G-actin, and it might be indirectly associated with delaying the aging of blood vessels.
MeSH Terms
- Actins
- Cell Cycle
- Cell Proliferation
- Cellular Senescence
- Cytoskeleton
- Drugs, Chinese Herbal
- Humans
- Muscle, Smooth, Vascular
- Myocytes, Smooth Muscle
- Panax
- Panax notoginseng
- Rhizome
Keywords
- cytoskeleton
- extracts of ginseng, notoginseng, and Chuanxiong Rhizoma
- senescence
- vascular aging
Objective To investigate the beneficial effect of Inula Britannica flower total flavonoids (IBFTF) on aging bone mesenchymal stem cell (BMSC) and its potential mechanism. Methods The aging BMSCs were induced by D-galactose, and then treated with 12.5, 25, 50 μg/mL IBFTF. The cell viability was detected by CCK-8 assay. The activity of catalase (CAT) and superoxide dismutase (SOD), the content of malondialdehyde (MDA) and reactive oxygen species (ROS) were measured by a commercial kit. The apoptosis was assessed by flow cytometry. The protein expressions of BAX, Bcl-2 and cleaved-caspase-3 (c-caspase-3) were determined by Western blotting. Results The cell viability and the activity of SOD and CAT in the aging group decreased significantly compared with the normal group, whereas different concentrations of IBFTF promoted the cell viability, and simultaneously increased the activity of SOD and CAT. The apoptosis, the ROS production, the content of MDA, BAX/Bcl-2 ratio and the protein expression of c-caspase-3 in the aging group increased obviously compared with the normal group. However, the treatment of different concentrations of IBFTF reduced the apoptosis, the ROS production, the content of MDA, BAX/Bcl-2 ratio and the protein expression of c-caspase-3. Conclusion IBFTF can attenuate the apoptosis of aging BMSCs by anti-oxidation.
MeSH Terms
- Aging
- Animals
- Antioxidants
- Apoptosis
- Bone Marrow Cells
- Flavonoids
- Flowers
- Inula
- Male
- Mesenchymal Stem Cells
- Plant Extracts
- Rats
- Rats, Sprague-Dawley
To explore the mechanism of excessive senescence in bone marrow-derived mesenchymal stem cells (BM-MSC) of mouse model with severe aplastic anemia (SAA) . 40 BALB/c mice were randomly assigned to two groups of control ([i]n[/i]=20) and AA ([i]n[/i]=20) . SAA mouse model was induced by intraperitoneal injection with IFN-γ and intragastric infusion with busulfan. BM-MSC were isolated and cultured from bone marrow of SAA and healthy mice. The cell morphology was observed by inverted microscope and cell cytoskeleton was stained by Rhodamine-Phalloidin; The level of proliferation was analyzed by CCK-8 method, and cell cycle was tested by flow cytometry. Senescence-associated β-galactosidase (SA-β-gal) assay was used to detect senescent BM-MSC; The expression of mTOR protein was detected by Western blot method. BM-MSC from normal mice presented spindle-shaped, clear boundaries and stress fibers were arranged in parallel, neat. while BM-MSCs from SAA mice presented cell volume increases, tiled, ill-shaped and the stress fiber appeared to be disordered. The decreased activity of proliferation [more cells restricted in G(0)/G(1) phase [ (77.461±1.567) % [i]vs[/i] (46.045±2.055) %, [i]t[/i]=-34.384, [i]P[/i]<0.001], increased percentage of SA-β-gal positive cells [ (75±11) % [i]vs[/i] (28±8) %, [i]t[/i]=15.454, [i]P[/i]<0.001] and notably enhanced expression of mTOR of BM-MSC from SAA mice were observed when compared with those from normal mice. This study clarified senescent BM-MSCs from SAA model mice, which could be caused by the excessive activation of mTOR pathway.
MeSH Terms
- Anemia, Aplastic
- Animals
- Bone Marrow
- Bone Marrow Cells
- Cell Cycle
- Cellular Senescence
- Disease Models, Animal
- Flow Cytometry
- Mesenchymal Stem Cells
- Mice
- Mice, Inbred BALB C
- Signal Transduction
Keywords
- Anemia, aplastic
- Mesenchymal stem cells
- Senescence
MicroRNAs are endogenously expressed, small non-coding RNAs that modulate gene expression by targeting specific mRNAs, resulting in translational repression or mRNA degradation. Although miR-584-5p has been reported to play a vital role in various malignancies, its role and the molecular mechanisms underlying the effects of miR-584-5p in gastric cancer (GC) remain to be clarified. In this study, we investigated the role of miR-584-5p in GC. The expression of miR-584-5p and its specific target gene were determined in human GC specimens and cell lines by microRNA real-time polymerase chain reaction (RT-PCR), quantitative RT-PCR (qRT-PCR) and Western blot. The effects of miR-584-5p depletion or ectopic expression on GC proliferation were evaluated in vitro using CCK-8 proliferation assays, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, colony formation assays and cell-cycle assays and the in vivo effects were investigated using a mouse tumorigenicity model. Cell apoptosis was evaluated by in vitro flow cytometric analysis, cell viability assays and in vivo TUNEL assays. Luciferase reporter assays were employed to identify interactions between miR-584-5p and its specific target gene. A series of in vitro and in vivo gain- and loss-of-function assays revealed that miR-584-5p inhibited GC cell proliferation, while apoptosis was induced. Luciferase reporter assays and Western blot analysis revealed WWP1 to be a direct target of miR-584-5p. The effects of miR-584-5p-mimic were rescued by WWP1 overexpression. In contrast, the effects of the miR-584-5p-inhibitor were impaired by WWP1-shRNA. Furthermore, miR-584-5p expression levels correlated negatively with WWP1 protein expression in GC tissues and GC cell lines. A series of investigations indicated that miR-584-5p promoted senescence and activated the TGFβ signaling pathway by downregulation of WWP1. Taken together, these results suggest that downregulation of miR-584-5p contributes to tumor progression by downregulation of WWP1, thus, highlighting the potential of miR-584-5p as a therapeutic target for human GC.
MeSH Terms
- 3' Untranslated Regions
- Animals
- Apoptosis
- Cell Line, Tumor
- Cell Proliferation
- Disease Progression
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Male
- Mice
- MicroRNAs
- Neoplasm Transplantation
- Signal Transduction
- Stomach Neoplasms
- Ubiquitin-Protein Ligases
- Up-Regulation
Keywords
- Apoptosis
- Cellular senescence
- Gastric cancer
- Proliferation
- TGFβ signaling pathway
- WWP1
- miR-584-5p
Overexpression of cyclin D1 dependent kinases 4 and 6 (CDK4/6) is a common feature of many human cancers including leukemia. LEE011 is a novel inhibitor of both CDK4 and 6. To date, the molecular function of LEE011 in leukemia remains unclear. Leukemia cell growth and apoptosis following LEE011 treatment was assessed through CCK-8 and annexin V/propidium iodide staining assays. Cell senescence was assessed by β-galactosidase staining and p16 expression analysis. Gene expression profiles of LEE011 treated HL-60 cells were investigated using an Arraystar Human LncRNA array. Gene ontology and KEGG pathway analysis were then used to analyze the differentially expressed genes from the cluster analysis. Our studies demonstrated that LEE011 inhibited proliferation of leukemia cells and could induce apoptosis. Hoechst 33,342 staining analysis showed DNA fragmentation and distortion of nuclear structures following LEE011 treatment. Cell cycle analysis showed LEE011 significantly induced cell cycle G arrest in seven of eight acute leukemia cells lines, the exception being THP-1 cells. β-Galactosidase staining analysis and p16 expression analysis showed that LEE011 treatment can induce cell senescence of leukemia cells. LncRNA microarray analysis showed 2083 differentially expressed mRNAs and 3224 differentially expressed lncRNAs in LEE011-treated HL-60 cells compared with controls. Molecular function analysis showed that LEE011 induced senescence in leukemia cells partially through downregulation of the transcriptional expression of MYBL2. We demonstrate for the first time that LEE011 treatment results in inhibition of cell proliferation and induction of G arrest and cellular senescence in leukemia cells. LncRNA microarray analysis showed differentially expressed mRNAs and lncRNAs in LEE011-treated HL-60 cells and we demonstrated that LEE011 induces cellular senescence partially through downregulation of the expression of MYBL2. These results may open new lines of investigation regarding the molecular mechanism of LEE011 induced cellular senescence.
Keywords
- Arraystar Human LncRNA array
- CDK4/6
- Cellular senescence
- LEE011
- Leukemia
Hydrogen sulfide (H2S), a third member of gasotransmitter family along with nitric oxide and carbon monoxide, generated from mainly catalyzed by cystathionine-lyase, possesses important functions in the cardiovascular system. Ischemic post-conditioning (PC) strongly protects against the hypoxia/reoxygenation (H/R)-induced injury and apoptosis of cardiomyocytes. However, PC protection is ineffective in the aging cardiomyocytes. Whether H2S restores PC-induced cardioprotection by decrease of reactive oxygen species (ROS) level in the aging cardiomyocytes is unknown. The aging cardiomyocytes were induced by treatment of primary cultures of neonatal cardiomyocytes using d-galactose and were exposed to H/R and PC protocols. Cell viability was observed by CCK-8 kit. Apoptosis was detected by Hoechst 33342 staining and flow cytometry. ROS level was analyzed using spectrofluorimeter. Related protein expressions were detected through Western blot. Treatment of NaHS (a H2S donor) protected against H/R-induced apoptosis, cell damage, the expression of cleaved caspase-3 and cleaved caspase-9, the release of cytochrome c (Cyt c). The supplementation of NaHS also decreased the activity of LDH and CK, MDA contents, ROS levels and the phosphorylation of IκBα, NF-κB, JNK2 and STAT3, and increased cell viability, the expression of Bcl-2, the activity of SOD, CAT and GSH-PX. PC alone did not provide cardioprotection in H/R-treated aging cardiomyocytes, which was significantly restored by the addition of NaHS. The beneficial role of NaHS was similar to the supply of N-acetyl-cysteine (NAC, an inhibitor of ROS), Ammonium pyrrolidinedithiocarbamate (PDTC, an inhibitor of NF-κB) and AG 490 (an inhibitor of JNK2), respectively, during PC. Our results suggest that exogenous H2S contributes to recovery of PC-induced cardioprotection by decrease of ROS level via down-regulation of NF-κB and JAK2/STAT3 pathways in the aging cardiomyocytes.
Keywords
- Aging cardiomyocytes
- Hydrogen sulfide
- Oxidative stress
- Post-conditioning
The paracrine effects of mesenchymal stem cells (MSCs) were weakened during aging. This study explored whether resveratrol can attenuate senescence of adipose-derived MSCs (ADMSCs) and whether Pim-1 is involved in resveratrol's effect on paracrine of ADMSCs and insulin secretion of INS-1 cells. CCK-8 assay and SA-b-gal assay were performed to test the protective effect of resveratrol on senescent models. QRT-PCR and western blot analysis were performed to analyze of senescence- and β-cell associated genes. QRT-PCR and ELISA analysis was performed to test telomere length and activity. Immunofluorescence and ELISA assay were performed to assess the paracrine effects on promoting insulin secretion of INS-1 cells. Resveratrol could protect ADMSCs from H2O2 and D-glucose-induced senescence and also attenuate senescence in long-term cultured ADMSCs in vitro. In addition, resveratrol attenuated H2O2 induced higher expression of senescence-associated genes, including P53, P21, Cyclin D1, IL-6 and MMP1, but increased the expression of Sirt1, a well-known anti-senescence gene. Resveratrol significantly enhanced Pim-1 expression in aging ADMSCs through PI3K/AKT signal pathway. The conditioned medium (CM) of ADMSCs enhanced insulin secretion and expression of the key genes for β-cell function including TFAM, PDX1, GLUT2 and HNF-1α via Pim-1. INS-1 cells with Pim-1 knockdown had decreased insulin secretion. This study firstly reported that resveratrol has a protective effect on senescence of ADMSCs and can preserve the paracrine effect of the ADMSCs on promoting insulin secretion of INS-1 cells via Pim-1. Therefore, it might be a promising adjuvant agent for future MSCs based therapy.
MeSH Terms
- Aging
- Animals
- Glucose
- Insulin
- Mesenchymal Stem Cells
- Proto-Oncogene Proteins c-pim-1
- Rats
- Resveratrol
- Stilbenes
- Transfection
Cholecystokinin (CCK) is a peptide hormone produced in the gut and brain with beneficial effects on digestion, satiety, and insulin secretion. CCK is also expressed in pancreatic β-cells, but only in models of obesity and insulin resistance. Whole body deletion of CCK in obese mice leads to reduced β-cell mass expansion and increased apoptosis. We hypothesized that islet-derived CCK is important in protection from β-cell apoptosis. To determine the specific role of β-cell-derived CCK in β-cell mass dynamics, we generated a transgenic mouse that expresses CCK in the β-cell in the lean state (MIP-CCK). Although this transgene contains the human growth hormone minigene, we saw no expression of human growth hormone protein in transgenic islets. We examined the ability of MIP-CCK mice to maintain β-cell mass when subjected to apoptotic stress, with advanced age, and after streptozotocin treatment. Aged MIP-CCK mice have increased β-cell area. MIP-CCK mice are resistant to streptozotocin-induced diabetes and exhibit reduced β-cell apoptosis. Directed CCK overexpression in cultured β-cells also protects from cytokine-induced apoptosis. We have identified an important new paracrine/autocrine effect of CCK in protection of β-cells from apoptotic stress. Understanding the role of β-cell CCK adds to the emerging knowledge of classic gut peptides in intraislet signaling. CCK receptor agonists are being investigated as therapeutics for obesity and diabetes. While these agonists clearly have beneficial effects on body weight and insulin sensitivity in peripheral tissues, they may also directly protect β-cells from apoptosis.
MeSH Terms
- Aging
- Animals
- Apoptosis
- Cell Line
- Cholecystokinin
- Cytokines
- Diabetes Mellitus, Type 2
- Down-Regulation
- Hyperglycemia
- Insulin
- Insulin Secretion
- Insulin-Secreting Cells
- Male
- Mice, Transgenic
- Promoter Regions, Genetic
- Rats
- Recombinant Proteins
- Streptozocin
- Stress, Physiological
- Tissue Culture Techniques
Keywords
- aging
- apoptosis
- cholecystokinin
- islet
- streptozotocin
- β-cell
Neurensin-2 (NRSN2) is a neuronal membrane protein; previous reports indicated that it might function as a tumor suppressor in hepatocellular carcinoma (HCC). However, its biological functions and associated mechanisms remain unknown. In the current study, we aimed to investigate the biological functions and possible mechanisms of neurensin-2. The mRNA and protein level of NRSN2 in HCC has tissues and cell lines were detected by quantitative real-time PCR, immunohistochemistry staning and western blot. Overexpressing and silencing the level of NRSN2 in HCC cell lines were used to investigate the role of NRSN2 in HCC. CCK-8 assays, SA-β gel staining, Annexin V/PI staining, quantitative real-time PCR and western blot were employed to explore the role and mechanisms of HCC. NRSN2 was more commonly down-regulated HCC tissues compared with adjacent tissues, and the expression pattern of NRSN2 was not only closely correlated with tumor size and TNM stage but also negatively correlated with patient prognosis. Both loss and gain function assays revealed that NRSN2 inhibits cancer cell proliferation and promotes cancer cell senescence and apoptosis. We further found that NRSN2 might regulate PI3K/AKT signaling and p53/p21 pathway to exert its role in HCC cell proliferation, senescence and apoptosis. Our study validates the suppressive role of NRSN2 in both clinicopathologic and biological aspects in HCC tumorigenesis.
MeSH Terms
- Adolescent
- Adult
- Aged
- Biopsy, Needle
- Blotting, Western
- Carcinoma, Hepatocellular
- Cell Proliferation
- Cell Survival
- Cellular Senescence
- Chi-Square Distribution
- Down-Regulation
- Gene Expression Regulation, Neoplastic
- Humans
- Immunohistochemistry
- Liver Neoplasms
- Membrane Proteins
- Middle Aged
- Phosphatidylinositol 3-Kinases
- Proto-Oncogene Proteins c-akt
- RNA, Messenger
- RNA, Small Interfering
- Real-Time Polymerase Chain Reaction
- Sampling Studies
- Sensitivity and Specificity
- Signal Transduction
- TOR Serine-Threonine Kinases
- Tumor Cells, Cultured
- Young Adult
Keywords
- Apoptosis
- Cell proliferation
- Cell senescence
- Hepatocellular carcinoma
- Neurensin-2
- Patient prognosis
Ginsenoside Rg1 (Rg1) is one of the most active ingredients in Panax ginseng and has been proven to have anti-oxidative and anti-aging properties. However, there have been few reports concerning the anti-aging effects of Rg1 on the hematopoietic microenvironment and bone marrow stromal cells (BMSCs). Thirty Sprague-Dawley rats were randomly divided into four groups (control, D-galactose (D-gal)-administration, Rg1-treatment, and D-gal-administration Rg1-treatment groups). After D-gal and Rg1 treatment, BMSCs were extracted from femoral bone marrow for culture. After three passages, BMSCs were tested by senescence-associated β-galactosidase (SA-β-gal) staining, flow cytometric cell cycle phase distribution assay, CCK-8 cell proliferation assay, oxidative stress (reactive oxygen species [ROS], superoxide dismutase [SOD], and malondialdehyde [MDA]) assays, inflammatory marker (interleukin (IL)-2, IL-6, and tumor necrosis factor (TNF)-α) enzyme-linked immunosorbent assay (ELISA), stem cell factor (SCF) ELISA, and senescence-associated protein (p16, p21, and p53) Western blotting. Compared to the D-gal-administration group, the D-gal-administration Rg1-treatment group showed significantly decreased levels of SA-β-gal cell %, ROS, MDA, inflammatory marker expression, and senescence-associated protein expression as well as significantly increased levels of S-phase %, cell proliferation, SOD activity, and SCF expression. Compared to controls, the Rg-1-treatment group displayed significantly reduced levels of SA-β-gal cell %, G1 phase %, ROS, MDA, inflammatory marker expression, senescence-associated protein expression, and SCF expression as well as significantly increased levels of S-phase %, cell proliferation, and SOD activity. Rg1 improves the anti-aging ability of hematopoietic microenvironment through enhancing the anti-oxidant and anti-inflammatory capacities of BMSCs.
MeSH Terms
- Aging
- Animals
- Anti-Inflammatory Agents
- Antioxidants
- Bone Marrow
- Cell Cycle
- Cell Proliferation
- Cellular Senescence
- Cytokines
- Galactose
- Ginsenosides
- Hematopoiesis
- Male
- Malondialdehyde
- Mesenchymal Stem Cells
- Models, Animal
- Oxidative Stress
- Panax
- Plant Extracts
- Rats, Sprague-Dawley
- Reactive Oxygen Species
- Stem Cell Factor
- beta-Galactosidase
Obesity is recognized as being multifactorial in origin, involving both genetic and environmental factors. The perinatal period is known to be critically important in the development of neural circuits responsible for energy homeostasis and the integration of autonomic reflexes. Diet-induced obesity alters the biophysical, pharmacological and morphological properties of vagal neurocircuits regulating upper gastrointestinal tract functions, including satiety. Less information is available, however, regarding the effects of a high fat diet (HFD) itself on the properties of vagal neurocircuits. The present study was designed to test the hypothesis that exposure to a HFD during the perinatal period alters the electrophysiological, pharmacological and morphological properties of vagal efferent motoneurones innervating the stomach. Our data indicate that perinatal HFD decreases the excitability of gastric-projecting dorsal motor nucleus neurones and dysregulates neurotransmitter release from synaptic inputs and that these alterations occur prior to the development of obesity. These findings represent the first direct evidence that exposure to a HFD modulates the processing of central vagal neurocircuits even in the absence of obesity. The perinatal period is critically important to the development of autonomic neural circuits responsible for energy homeostasis. Vagal neurocircuits are vital to the regulation of upper gastrointestinal functions, including satiety. Diet-induced obesity modulates the excitability and responsiveness of both peripheral vagal afferents and central vagal efferents but less information is available regarding the effects of diet per se on vagal neurocircuit functions. The aims of this study were to investigate whether perinatal exposure to a high fat diet (HFD) dysregulated dorsal motor nucleus of the vagus (DMV) neurones, prior to the development of obesity. Whole cell patch clamp recordings were made from gastric-projecting DMV neurones in thin brainstem slices from rats that were exposed to either a control diet or HFD from pregnancy day 13. Our data demonstrate that following perinatal HFD: (i) DMV neurones had decreased excitability and input resistance with a reduced ability to fire action potentials; (ii) the proportion of DMV neurones excited by cholecystokinin (CCK) was unaltered but the proportion of neurones in which CCK increased excitatory glutamatergic synaptic inputs was reduced; (iii) the tonic activation of presynaptic group II metabotropic glutamate receptors on inhibitory nerve terminals was attenuated, allowing modulation of GABAergic synaptic transmission; and (iv) the size and dendritic arborization of gastric-projecting DMV neurones was increased. These results suggest that perinatal HFD exposure compromises the excitability and responsiveness of gastric-projecting DMV neurones, even in the absence of obesity, suggesting that attenuation of vago-vagal reflex signalling may precede the development of obesity.
MeSH Terms
- Action Potentials
- Aging
- Animals
- Brain Stem
- Diet, High-Fat
- Female
- In Vitro Techniques
- Male
- Motor Neurons
- Obesity
- Potassium Channels, Voltage-Gated
- Rats, Sprague-Dawley
- Receptors, Metabotropic Glutamate
- Stomach
- Vagus Nerve
Keloids are one of the common refractory conditions in dermatology and aesthetic plastic surgery. The most effective treatment is superficial radiotherapy followed by surgical removal. The rate of recurrence is strongly associated with the total dose of ionizing irradiation, and the underlying mechanism remains unclear. In this study, we used primary keloid fibroblasts (KFb) isolated from patient samples to investigate the effects of X-ray radiation on cell proliferation, cell toxicity and cell cycle, as detected by CCK-8 assay kit and flow cytometer. In addition, we examined senescence-associated β-galactosidase activity and the associated gene expression using real-time polymerase chain reaction and western blot in KFb exposed to X-ray radiation. X-ray radiation inhibited cell proliferation and induced cell senescence in KFb in a dose-dependent manner. Inhibition of cell proliferation and induction of cellular senescence were mediated by interruption of the cell cycle with an extended G0/G1 phase. Furthermore, the expressions of senescence-associated genes p21, p16 and p27 were upregulated both at mRNA and protein levels in KFb exposed to X-ray radiation. Taken together, our data indicate that X-ray radiation may prevent the recurrence of keloids by controlling fibroblast proliferation, arresting the cell cycle and inducing premature cellular senescence.
MeSH Terms
- Adolescent
- Adult
- Cell Cycle
- Cell Proliferation
- Cells, Cultured
- Cellular Senescence
- Child
- Female
- Fibroblasts
- Humans
- Keloid
- Male
- X-Ray Therapy
- Young Adult
Keywords
- cell cycle
- cellular senescence
- ionizing irradiation
- primary keloid fibroblast
Cholecystokinin (CCK) is anorexic, irrespective whether it is applied intraperitoneally (IP) or intracerebroventricularly (ICV) in male Wistar rats. The metabolic effects depend on the route of administration: by the IP route it elicits hypothermia (presumably by type-1 receptors, CCK1R-s), while ICV administration is followed by fever-like hypermetabolism and hyperthermia via activation of CCK2R-s, which latter response seems to be most important in the postprandial (compensatory) hypermetabolism. The efficacy of the IP injected CCK varies with age: it causes strong anorexia in young adult 4 and 6-months old and again in old rats (aged 18-24 months), but the middle-aged (12-month old) ones seem to be resistant to this effect. Such pattern of effects may contribute to the explanation of age-related obesity observed in middle-aged animals as well as to the aging anorexia and loss of body weight in old ones. Diet-induced obesity accelerates the appearance of CCK-resistance as well as the return of high sensitivity to CCK in further aging, while chronic calorie-restriction prevents the development of resistance, as if the speed of the age-related regulatory changes was altered by the nutritional state. The effects of ICV applied CCK also change with age: the characteristic anorexic and hypermetabolic/hyperthermic effects can be observed in young adult rats, but the effects gradually and monotonically decline with age and disappear by the old age of 24 months. These disparate age-related patterns of CCK efficacy upon peripheral or central administration routes may indicate that although both peripheral and central CCKR-s exert anorexic effects, they may have dissimilar roles in the regulation of overall energy balance.
MeSH Terms
- Aging
- Animals
- Anorexia
- Body Temperature Regulation
- Body Weight
- Caloric Restriction
- Cholecystokinin
- Diet, High-Fat
- Eating
- Energy Metabolism
- Injections, Intraperitoneal
- Injections, Intraventricular
- Male
- Nutritional Status
- Obesity
- Rats
- Rats, Wistar
Keywords
- Aging
- Calorie-restriction
- Cholecystokinin
- Food intake
- Metabolic rate
- Obesity
Gut functions, such as gastrointestinal motility, gastric secretion and pancreatic secretion, were reduced with age. Glucose tolerance is impaired, and the release of insulin and β-cell's sensitivity on glucose are reduced with age. However, a lot of controversial data have been reported as insulin concentrations after glucose ingestion are either higher or no different in elderly and young subjects. Thus, this study was aimed to investigate whether aging could affect pancreatic exocrine secretion and its action mechanisms. An isolated perfused rat pancreatic model was used to exclude the effects of external nerves or hormones. Pancreatic secretion was increased by CCK under 5.6 mM glucose background in the isolated perfused pancreas of young (3 months), 12 months and 18 months aged rats. There was no significant difference between young and aged rats. In 3 months old rats, CCK-stimulated pancreatic secretion was potentiated under 18 mM glucose background. However, the potentiation effects of endogenous insulin and CCK were not observed in 12 and 18 months old rats. Exogenous insulin also potentiated CCK-stimulated pancreatic secretion in 3 months old rats. Similarly, exogenous insulin failed to potentiate CCK-stimulated pancreatic secretion as that of 3 months old rats. Wet weight of pancreas and amylase content in pancreatic tissue were not changed with age. These results indicate that pancreatic exocrine secretion is reduced with age and endogenous insulin secretion and/or action is involved in this phenomenon.
Keywords
- Aging
- cholecystokinin
- exocrine secretion
- glucose
- insulin
Obesity of middle-aged mammals is followed at old age by anorexia and cachexia leading to sarcopenia. Complex age- and body composition-related alterations in the regulation of energy homeostasis may be assumed in the background. We aimed to test the possible contribution of age- and body composition-related changes of satiety responses to catabolic brain-gut-axis peptide cholecystokinin (CCK) to these alterations in energy balance during aging. Male Wistar rats (6-8 animals/group) aged 2 months (juvenile), 3 months (young adult), 6 or 12 months (early or late middle-aged), and 24 months (old) were injected intraperitoneally with 5 μg CCK-8 prior to re-feeding after 48-h food-deprivation. CCK suppressed re-feeding in young adult (26.8%), early middle-aged (35.5%), and old (31.4%) animals, but not in juvenile or late middle-aged rats (one-way ANOVA). CCK-resistance of 12 months old rats was prevented by life-long calorie-restriction: CCK suppressed their re-feeding by 46.8%. Conversely, in highfat diet-induced obese 6 months old rats CCK failed to suppress re-feeding. In conclusion, age-related changes in satiety responsiveness to CCK may contribute to the age-related obesity of middle-aged as well as to the anorexia of old animals. CCK-responsiveness is also influenced by body composition: calorie-restriction prevents the resistance to CCK, pre-existing obesity enhances it.
MeSH Terms
- Adiposity
- Age Factors
- Aging
- Animals
- Anorexia
- Body Composition
- Caloric Restriction
- Diet, High-Fat
- Energy Metabolism
- Feeding Behavior
- Homeostasis
- Injections, Intraperitoneal
- Male
- Obesity
- Rats
- Rats, Wistar
- Satiety Response
- Sincalide
Loss of appetite is frequently observed during ageing, termed the 'anorexia of ageing'. Ageing is associated with the inability to appropriately increase food intake after under-eating in the short- and long-term. Older people also report lower feelings of hunger and increased feelings of satiety and fullness. Gastrointestinal peptide hormones are a major part of the appetite regulatory system and are released in response to nutritional stimuli. They can be classified as: anorexigenic (satiety) [e.g. peptide tyrosine tyrosine (PYY), glucagon-like peptide-1, pancreatic polypeptide, oxyntomodulin and cholecystokinin (CCK)] or orexigenic (hunger) (e.g. ghrelin). Although the control of appetite is not fully understood, it is clear that these hormones play an important role, and may influence the development and treatment of obesity and under-nutrition. The literature shows a consistent finding that there is a loss of appetite in those aged over 65 years, although how this loss is mediated is not yet clear. Some evidence suggests that with advancing age there is an increase in satiety hormones, such as CCK and PYY, and a decrease in the hunger hormone, ghrelin. However, not all studies agree, emphasising the need for more in-depth research to clarify age-related changes. This knowledge will enable us to develop therapies to help prevent under-nutrition during ageing. This review explores how age influences gastrointestinal appetite hormones in humans, as well as how this may contribute to the development of age-related malnutrition.
MeSH Terms
- Aged
- Aging
- Anorexia
- Appetite Regulation
- Energy Intake
- Gastrointestinal Hormones
- Humans
- Malnutrition
- Obesity
- Satiety Response
Decreased energy intake in older persons poses these people at risk of progressive weight loss. It may result from a failure to regulate energy intake and expenditure after periods of underfeeding. The objective of this study was to investigate if a period of underfeeding differentially influences energy intake of older compared with young men and, additionally, to study potential underlying mechanisms, namely changes in gastric emptying rate and cholecystokinin (CCK) levels in blood. Dietary intervention of 3 phases. After a phase of energy balance, we fed participants in phase 2 by a mean of 70% of their needs for 21 days. During phase 3, we assessed ad libitum energy intake of the participants during 9 days. At the end of phases 1 and 2, we assessed appetite, gastric emptying, and CCK levels in blood in response to a test meal. Fifteen young (age 24 years [range 20-34], body mass index 23.0 kg/m(2) ± 2.3) and 17 older (age 68 years [64-85], body mass index 24.5 kg/m(2) ± 1.9) men participated in this study. During energy balance, mean energy intake of young men (14.3 ± 2.3 MJ/day) was significantly higher than that of older men (11.3 ± 1.8 MJ/day, P < .001). After the period of underfeeding, energy intake in phase 3 amounted to 16.3 ± 2.6 MJ/day in young men and to 14.4 ± 3.2 MJ/day in older men. Ad lib energy intake after underfeeding did not differ between young and older men (analysis of covariance, with energy intake during phase 1 as covariate, P = .99). There were no differential changes in body weight, body composition, resting energy expenditure, gastric emptying rate, CCK-8 levels, and appetite between young and older men during the study. Our results do not indicate that older men have an impaired ability to control energy intake after a period of underfeeding compared with younger men. NCT00561145.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Anthropometry
- Body Composition
- Cholecystokinin
- Energy Intake
- Energy Metabolism
- Gastric Emptying
- Humans
- Male
- Malnutrition
- Motor Activity
- Young Adult
Human aging is associated with a reduction in appetite and food intake. Increased activity of the satiety hormone, cholecystokinin (CCK), may be partly responsible. This study aimed to determine whether an increase in fat and energy intake modifies the suppressive effects of CCK-8 on appetite and energy intake. Fourteen healthy older adults completed three separate dietary periods, a 14-day and a 7-day normal diet (ND; 8272 ± 480 kJ/day; 35% fat), and a 14-day high-fat diet (HFD; 11,642 ± 414 kJ/day; 43% fat), in randomised order. Immediately following each diet, subjects received, in single-blinded fashion, a 30-min intravenous infusion of either CCK-8 (1.5 ng/kg/min) (ND-CCK, HFD-CCK) or 0.9% saline (ND-SAL), the latter following only ND. Plasma CCK concentrations, appetite responses and energy intake at a buffet meal were determined. Energy intake at the buffet meal was higher on the ND-SAL study day (3349 ± 224 kJ), when compared with either ND-CCK (3023 ± 317 kJ) or HFD-CCK (2905 ± 316 kJ). The suppression of energy intake by CCK-8 infusion did not differ between the two diets. We conclude that suppression of energy intake by exogenous CCK-8 does not appear to be attenuated by incorporation of supplemental high-energy, high-fat drinks in the diet of healthy older adults.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- Appetite
- Cholecystokinin
- Dietary Fats
- Dietary Supplements
- Energy Intake
- Female
- Humans
- Infusions, Intravenous
- Male
- Single-Blind Method
The results of extensive human and animal studies suggest that declining food intake and body weight observed in the later stages of life may be part of the normal progression of physiological decline observed during aging. Proposed etiologies cover a wide range of biological and psychological conditions. Studies in humans suggest an imbalance in homeostatic mechanisms governing hunger and satiety. That is, while older vs. younger individuals retain a similar drive (hunger) to eat, satiety occurs sooner during a meal in aged people and leads to an overall decrease in daily food intake. Age-related weight loss and a reduction in food intake have also been observed in laboratory animals. Alterations in neurochemical control of energy balance, especially as they relate to long-term regulation of food intake, have received much attention in recent years as the likely mechanism underlying age-related spontaneous weight loss. Age-related changes to neuroendocrine factors such as neuropeptide Y, GABA, CCK, leptin, and insulin have been linked to spontaneous weight loss observed during late life. This brief review provides an update on putative mechanisms underlying the dysregulation of feeding during advanced age that result in body weight loss.
MeSH Terms
- Adult
- Aged
- Aging
- Appetite Regulation
- Eating
- Energy Metabolism
- Homeostasis
- Humans
- Hypothalamus
- Middle Aged
- Weight Loss
- Young Adult
Aging is associated with a progressive decrease in appetite and food intake. The reasons for the decline in food intake are multifactorial, and relate to both peripheral and central mechanisms. Current studies about the regulation of food intake suggest that there are many central mediators that control the appetite. To determine the mechanism of age-associated decrease in appetite and food intake, we focused on the age-associated changes of the suppressing and stimulatory effect of some appetite-regulating peptides. At first, we examined cholecystokinin (CCK), one of the typical appetite-suppressing factors. Although sensitivity to CCK is enhanced in old animals, the mechanism underlying this effect has not been elucidated. Next, we focused on the appetite-stimulating peptides, orexin-A, neuropeptide Y (NPY) and ghrelin, which are known to play a critical role in food intake. To determine the age-associated decrease in appetite and food intake, we compared the stimulatory effect of intracerebroventricular administration of orexin-A, NPY and ghrelin. We report the studies of the age-associated changes of appetite-regulating peptides in this review.
MeSH Terms
- Aging
- Animals
- Appetite
- Blotting, Western
- Cholecystokinin
- Eating
- Ghrelin
- Hypothalamus
- Intracellular Signaling Peptides and Proteins
- Neuropeptide Y
- Neuropeptides
- Orexins
- Rats
- Rats, Wistar
- Sympathomimetics
The current study sought to clarify the role of cholecystokinin (CCK) in the digestion of larval red drum (Sciaenops ocellatus) in order to better characterize the processes limiting the utilization of microparticulate diets at first feeding. The red drum CCK cDNA, isolated from adult anterior intestine and pyloric caeca, contains a 414 base pair (bp) open reading frame encoding a deduced amino acid sequence of 138 residues which is highly similar to preprocholecystokinin from other vertebrates. The mature CCK octapeptide has the same amino acid sequence as that found in mammals and in Atlantic herring (Clupea harengus). Tissue distribution analysis of adult and juvenile red drum using primers specific for red drum CCK mRNA revealed bright bands in samples from the brain, pyloric caeca, anterior intestine, and gonad with fainter bands seen in all other tissues. Immunohistochemical analysis of larval red drum showed that CCK-immunoreactive (CCK-IR) cells were present as early as 3 days post hatch (DPH) in some fish and were present in all fish by 6 DPH. CCK-IR cells were found in the anterior midgut in early larvae and had spread to the first bend of the gut by day 6. In older larvae (18 DPH), CCK-IR cells were found in large numbers in the anterior intestine and in the developing pyloric caeca. The sequence and distribution of CCK mRNA along with the presence of CCK-IR cells in early red drum larvae suggest that CCK is present and may be capable of regulating pancreatic secretion in early red drum larvae.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Brain
- Cholecystokinin
- Cloning, Molecular
- Gastrointestinal Tract
- Gonads
- Larva
- Molecular Sequence Data
- Perciformes
- Protein Precursors
- Sequence Alignment
The increased palatability of modern diet contributes to eating beyond homeostatic need and in turn to the growing prevalence of obesity. How palatability is coded in taste-evoked neural activity and whether this activity differs between obese and lean remains unknown. To investigate this, we used extracellular single-unit recording in the second central gustatory relay, the pontine parabrachial nucleus while stimulating the tongue with various concentrations of sucrose (0.01-1.5 M) in Otsuka Long Evans Tokushima Fatty (OLETF) rats, lacking CCK-1R. The analyses included a total of 179 taste-responsive neurons in age-matched prediabetic, obese OLETF and lean Long Evans Tokushima Otsuka (LETO) controls. Compared with LETO, we found more NaCl-, and fewer sucrose-responsive neurons (67 vs. 47% and 14 vs. 32%), and an overall reduced response magnitude to sucrose in the OLETF rats. Further, in the obese rats there was a rightward shift in sucrose concentration-response functions relative to lean controls with a higher response-threshold (0.37 /-0.05 vs. 0.23 /-0.2 M, P<0.05) and maximal neural response to higher sucrose concentrations (0.96 /-0.07 vs. 0.56 /-0.5 M, P<0.001). These findings demonstrate altered central gustatory processing for sucrose in obese OLETF rat and further support the notion that palatability is encoded in the across neuron pattern.
MeSH Terms
- Adiposity
- Aging
- Animals
- Body Composition
- Body Weight
- Cluster Analysis
- Data Interpretation, Statistical
- Dose-Response Relationship, Drug
- Electrophysiology
- Glucose Tolerance Test
- Male
- Motivation
- Neurons
- Obesity
- Pons
- Rats
- Rats, Inbred OLETF
- Sucrose
- Taste
Information regarding age-induced Ca(2 ) signal alterations in nonexcitable cells is limited. In addition, little evidence exists on the ability of melatonin to palliate the effects of aging on Ca(2 ) signals and mitochondrial potential, a parameter involved in both Ca(2 ) signaling and aging. We studied the ability of melatonin to prevent the effects of aging on intracellular Ca(2 ) homeostasis and mitochondrial potential in exocrine cells. Pancreatic acinar cells were obtained from adult (3 months old) and aged (22-24 months old) mice by collagenase dispersion. Ca(2 ) signals, in situ mitochondrial potential and in vitro amylase secretion were determined. Secretion in response to increasing levels of the secretagogues, acetylcholine and cholecystokinin (CCK), were impaired in aged pancreatic acini. This decrease was accompanied by an inhibition in the amplitude of the peak response to maximal concentrations of the agonists, and by a decrease in the pattern of Ca(2 ) oscillations induced by postprandial levels of CCK. Both the size of the calcium pools, assessed by low levels of ionomycin, and capacitative calcium entry, induced by depletion of the stores with thapsigargin, were diminished in aged cells. These changes in Ca(2 ) homeostasis were associated with depolarization of intracellular mitochondria. Oral administration of melatonin for 3 months to aged mice restored the secretory response, the amplitude and frequency of Ca(2 ) responses, the size of intracellular calcium pools, the capacitative calcium entry, and the mitochondrial potential. In conclusion, melatonin restores secretory function, Ca(2 ) signals and mitochondrial potential of aged exocrine cells.
MeSH Terms
- Acetylcholine
- Aging
- Amylases
- Animals
- Antioxidants
- Calcium Signaling
- Cells, Cultured
- Cholecystokinin
- Exocrine Glands
- Melatonin
- Membrane Potential, Mitochondrial
- Mice
Otsuka Long-Evans Tokushima fatty (OLETF) rats are a strain of Long-Evans Tokushima Otsuka (LETO) rats that do not express CCK-1 receptors, developing in adulthood, hyperphagia, obesity, and non-insulin-dependent diabetes mellitus (NIDDM). We examined weight gain and meal patterns during a 30-min independent ingestion test on postnatal days 2-4 and again on days 9-11 in OLETF and LETO rat pups. OLETF pups were significantly heavier compared with their LETO controls at both ages, and they consumed significantly more of the sweet milk diet. The difference in intake can be attributed to a significant increase in meal size and duration. Number of clusters and bursts of licking within a meal were greater in OLETF rat pups, with no difference between strains in burst and cluster size. Interlick interval (ILI) was not significantly different between OLETF and LETO pups. This measure decreased on days 9-11 compared with days 2-4 in both strains. Latency to start feeding was significantly shorter on days 2-4 in OLETF vs. LETO pups, but this difference disappeared at the second test at the older age. Two- to four-day-old OLETF pups consumed a larger volume of milk during the first minute of feeding, and their initial lick rate and decay of lick rate were significantly larger compared with their LETO controls. Lack of CCK-1 receptors, or other OLETF-related abnormalities, therefore, resulted in a satiation deficit, leading to increased meal size, hyperphagia, and increased weight gain as early as 2-4 postnatal days.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Diet
- Feeding Behavior
- Rats
- Rats, Inbred OLETF
- Rats, Long-Evans
- Receptor, Cholecystokinin A
- Time Factors
- Weight Gain
Neurons in the principal bed nucleus of the stria terminalis (BSTp) integrate hormonal and sensory information associated with reproduction and transmit this information to hypothalamic nuclei that regulate neuroendocrine and behavioral functions. The neuropeptides galanin (GAL), cholecystokinin (CCK), and substance P (SP) are highly expressed in BSTp neurons and are differentially regulated by sex steroids. The current experiments investigated whether developmental or peripubertal hormone-mediated changes in GAL, CCK, and SP expression are reflected within efferent pathways to the preoptic structures that regulate gonadotropin secretion and sexual behavior. Anterograde labeling of projections from the BSTp of male and female juvenile rats combined with immunohistochemical labeling of GAL-, CCK-, and SP-containing fibers in the anteroventral periventricular preoptic nucleus (AVPV) and the central and medial divisions of the medial preoptic nucleus (MPNc, MPNm, respectively) revealed unique sex differences in each region. In the AVPV, Phaseolus vulgaris leucoagglutinin-labeled fibers were seen at a greater density in males than in females, and higher percentages of these fibers contained GAL in males than in females. In contrast, fibers projecting from the BSTp to the MPNc were more likely to contain SP in females than in males. Treatment of gonadectomized, peripubertal males and females with exogenous testosterone and estradiol did not alter the densities of GAL-, CCK-, or SP-containing fibers in any of the three brain areas examined. Collectively, these results suggest that patterns of neuropeptide expression in BSTp projections are established during development, resulting in a distinct, stable, and sex-specific chemoarchitectural profile for each projection pathway.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Efferent Pathways
- Female
- Galanin
- Immunohistochemistry
- Male
- Neurons
- Neuropeptides
- Phytohemagglutinins
- Preoptic Area
- Presynaptic Terminals
- Rats
- Rats, Sprague-Dawley
- Septal Nuclei
- Sex Characteristics
- Sexual Maturation
- Substance P
Aging is associated with a reduction in appetite and food intake, predisposing to protein-energy malnutrition. The causes of this "anorexia of aging" are largely unknown. To investigate possible contributions of enhanced satiating effects of cholecystokinin (CCK) and reduced stimulation of food intake by ghrelin, eight undernourished older women [age, 80.4 /- 2.6 yr; body mass index (BMI), 16.9 /- 0.57 kg/m(2)], eight well-nourished older women (age, 77 /- 0.9 yr; BMI, 23.7 /- 0.8 kg/m(2)), and eight well-nourished young women (age, 22 /- 1.3 yr; BMI, 20.5 /- 0.4 kg/m(2)), in randomized order, ate on 1 d a 280-kCal preload and on the other no preload, 90 min before an ad libitum meal. At baseline the undernourished, but not the well-nourished, older subjects were less hungry (P < 0.05) than young subjects. Before and after the preload, plasma CCK levels were higher (P < 0.05) in the older than young subjects, with no difference between the older groups. Plasma ghrelin concentrations were higher in the undernourished than both well-nourished groups and decreased similarly after the preload in all groups. The preload suppressed food intake in the well-nourished older and young subjects (P < 0.05), but was without effect in the undernourished old. These observations suggest that reduced basal hunger, rather than increased meal-induced satiety, contributes to the anorexia of aging and that changes in CCK and ghrelin are unlikely to be responsible.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- Appetite
- Blood Glucose
- Cholecystokinin
- Dietary Carbohydrates
- Dietary Fats
- Eating
- Energy Metabolism
- Female
- Gastrointestinal Hormones
- Ghrelin
- Humans
- Nutrition Disorders
- Peptide Hormones
- Satiety Response
We investigated the changes in the capacity for synthesis of the exocrine pancreas of piglets during the 2 wk after weaning at 7 d of age (trial 1) by measuring the expression of digestive enzymes at mRNA and activity levels in pancreas homogenates, and the effects of high and low feed intakes during the 1st wk postweaning (trial 2) on these measures. The trypsin mRNA level was transiently decreased 43% 3 d postweaning (P < 0.05). Thereafter, trypsin and lipase mRNAs linearly increased (P < 0.05). During the 1st wk postweaning, trypsin- and lipase-specific activities were reduced 44 and 79% (P < 0.05), respectively, whereas 14 d after weaning, trypsin was at the preweaning value and lipase was at a low level. Amylase-specific activity did not change with weaning. Plasma cholecystokinin (CCK) and gastrin concentrations decreased 1 d postweaning and increased afterward up to 3 and 5 d postweaning, respectively. By 3 d after weaning, the mRNA level of trypsin was twofold higher (P < 0.05) in piglets that consumed more feed than in those that consumed less, whereas 7 d after weaning, the groups did not differ. By 7 d after weaning, the specific activity of amylase was higher, and lipase-specific activity was lower, in piglets that consumed more feed than in those that consumed less. Plasma CCK and gastrin concentrations measured 7 d after weaning were correlated with feed intake (r = 0.56 and r = 0.68, P < 0.05, respectively). In conclusion, by 3 d postweaning, pancreatic exocrine function was adapting to the new diet. Afterward, the expression of specific genes coding digestive enzymes and the levels of pancreatic enzyme activities were restored or stimulated, except for lipase-specific activity. Therefore, the pancreas can adjust to weaning and dry food intake as early as wk 2 of life.
MeSH Terms
- Aging
- Animals
- Body Weight
- Cholecystokinin
- Eating
- Female
- Gene Expression Regulation, Enzymologic
- Lipase
- Male
- Pancreas
- Pancreatin
- RNA, Messenger
- Swine
- Trypsin
- Weaning
Older age is associated with diminished symptomatic and cardiovascular response to the panicogenic agent cholecystokinin tetrapeptide (CCK-4). We hypothesized that circulating concentrations of endogenous CCK-4 and/or CCK-8 are increased in later life, possibly due to decreased enzymatic degradation, and that this is associated with desensitization of CCK-B receptors. The study group consisted of 20 healthy subjects aged 18-30 years and 20 healthy subjects aged 65-85 years. The two groups were compared on fasting basal plasma concentrations of CCK-4, sulfated CCK-8 (CCK-8s) and nonsulfated CCK-8 (CCK-8 ns), and on binding capacity of lymphocyte CCK-B receptors. Under single-blind (to subject) conditions, subjects were then administered an intravenous bolus of placebo, followed 50 min later by an intravenous bolus of 50 micro g of CCK-4. Plasma concentrations of total CCK (CCK(T)) were measured 2 min before and 2, 5, 10, and 15 min after each injection. Compared with younger subjects, older subjects had a significantly higher basal plasma concentration of CCK-8s and significantly diminished binding capacity of CCK-B receptors. Following injection of placebo, plasma CCK(T) concentrations did not significantly change from baseline in either age group, but the elderly had significantly higher concentrations than the young at 2, 5, and 10 min. Following injection of CCK-4, the plasma concentration of CCK(T) was highest at 2 min and declined after that. The elderly had significantly higher CCK(T) concentrations (ie. a slower decline in CCK(T)) than the young at 5, 10, and 15 min. These findings are consistent with our hypothesis and suggest that age-related changes in the CCK system could contribute to the diminished panicogenic response to exogenous CCK-4 in older persons.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Brain
- Cardiovascular Physiological Phenomena
- Female
- Humans
- Lymphocytes
- Male
- Middle Aged
- Panic Disorder
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
- Sincalide
- Tetragastrin
Ageing is associated with a reduction in appetite and food intake, which has been termed the 'anorexia of ageing'. After age 70-75 years average body weight decreases, even in healthy people, disproportionately due to loss of lean tissue. The 'physiological' anorexia and weight loss of ageing predispose to pathological weight loss and malnutrition. Marked weight loss is common in the elderly and a major cause of morbidity and increased mortality. The cause(s) of the anorexia of ageing are largely unknown. We have identified several possibilities. Animal and preliminary human studies indicate that ageing is associated with increased satiety factors and a reduced feeding drive. Endogenous opioids stimulate eating. We administered i.v. infusions of the opioid antagonist naloxone to young and older adults. Overall, the suppression of food intake was not different in the two age groups, but was increased in older women, suggesting reduced stimulation of feeding by endogenous opioids in this group. Plasma concentrations of the satiety hormone cholecystokinin (CCK) increase with ageing. Intravenous CCK-8 infusion produced greater suppression of food intake in older than young subjects (33.5 vs 15.5% P = 0.026), indicating that sensitivity to the satiating effects of CCK is at least maintained and may increase with age. This raises the possibility of using CCK antagonists as stimulants of appetite and food intake in malnourished older people.
MeSH Terms
- Aged
- Aging
- Animals
- Anorexia
- Cholecystokinin
- Female
- Humans
- Male
In order to know the effects of weaning and volatile fatty acid feeding on gastric leptin expression, we investigated the expression of leptin and CCK receptor mRNA in the bovine rumen, abomasum and duodenum using RT-PCR in 3-week-old pre-weaning, 13-week-old post-weaning and adult animals. Leptin mRNA was expressed in the rumen and abomasum of 3-week-old pre-weaning animals, but it was abolished in 13-week-old and adult animals. In the duodenum, leptin expression was observed in the 3-, 13-week-old and adult animals. In the rumen, CCK(A) receptor mRNA was expressed in 3-week-old animals, but not in 13-week-old and adult animals. In the abomasum, CCK(B) receptor expression gradually decreased from 3-week-old to adult animals. Expression of CCK(B) receptor and of CCK(A) receptor was slight in the rumen and abomasum, respectively. In the next study, we examined the effect of weaning of 6 weeks or non-weaning (fed on milk replacer alone (milk) or milk replacer with volatile fatty acids (milk VFA) until 13 weeks old) on leptin mRNA expression in the rumen and abomasum. In 13-week-old calf rumen and abomasum, leptin mRNA expression was detected in non-weaning milk-fed animals at 13 weeks old, although it was not observed in weaning and non-weaned milk VFA-fed animals. The change in CCK(A) receptor expression in the rumen was similar to those of leptin mRNA expression. CCK(B) receptor transcription in the abomasum of milk-fed animals was higher than that of the weaning and milk VFA-fed animals. These results indicate that leptin expression is coincident with CCK receptor expression in calf stomachs, and that leptin and CCK receptor mRNA expression are affected by the change in the physiological status brought about by weaning and VFA feeding.
MeSH Terms
- Abomasum
- Aging
- Animals
- Cattle
- Gene Expression
- Leptin
- Male
- Nutritional Status
- RNA, Messenger
- Receptor, Cholecystokinin A
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
- Rumen
- Weaning
Peroxisome proliferator-activated receptors (PPARs) are a family of ligand-activated nuclear transcription factors belonging to the nuclear hormone receptors. Troglitazone, a specific ligand for PPAR-gamma is shown to regulate not only lipids and glucose metabolism, but also cell cycle, differentiation, and apoptosis. To examine the effect of chronic oral administration of troglitazone on the age-related changes of insulin resistance, plasma CCK levels, and pancreatic growth in normal rats. A troglitazone-rich diet (0.2%) was given from 12 to 28 weeks of age or from 12 or 28 weeks of age to 72 weeks of age. Fasting serum glucose concentrations in control rats increased progressively with age, which was almost completely prevented by troglitazone treatment. Serum insulin concentrations and pancreatic insulin content in the control rat markedly increased at 28 weeks of age but decreased at 72 weeks of age. These parameters in troglitazone-treated rats remained at nearly the same concentrations at all ages. Insulin concentration relative to DNA in the control rats increased with age, whereas in the troglitazone-treated rats it remained at nearly the same concentrations throughout the observation periods and was significantly lower than that in the controls. Insulin resistance in control rats showed a great increase at 72 weeks of age, whereas it was nearly the same at all ages in troglitazone-treated rats and was significantly lower than those in the control rats. Plasma cholecystokinin concentrations in control rats slightly but insignificantly increased with age, whereas pancreatic weight decreased age-dependently when corrected for body weight. Although troglitazone treatment appeared to decrease plasma cholecystokinin concentrations compared with those in the control rats, it significantly increased pancreatic weight and prevented age-dependent decrease. Troglitazone treatment significantly increased pancreatic protein and DNA contents, but the protein per DNA ratio, an indicator of cellular size, remained at nearly the same concentrations at all ages. The contour of the islets in the control rats at 72 weeks of age was somewhat irregular with structural disarrangement and fibrosis. Moreover, the islets were separated into small sections (cluster) by fibrosis. Troglitazone treatment prevented or reversed these age-related changes of the islets to those in rats at 12 weeks of age. Our results indicate that troglitazone stimulates pancreatic growth in the normal rat not only by reducing insulin resistance and improving glucose metabolism, but also by suppressing fibrosis of the islets.
MeSH Terms
- Aging
- Alanine Transaminase
- Amylases
- Animals
- Aspartate Aminotransferases
- Blood Glucose
- Body Weight
- Cholecystokinin
- Chromans
- DNA
- Diet
- Eating
- Hypoglycemic Agents
- Insulin
- Insulin Resistance
- Liver
- Male
- Organ Size
- Pancreas
- Proteins
- Rats
- Rats, Long-Evans
- Receptors, Cytoplasmic and Nuclear
- Thiazoles
- Thiazolidinediones
- Transcription Factors
- Troglitazone
There has been considerable interest in gall bladder motility in recent years. We compared the effects of cholecystokinin (CCK) and erythromycin on bile chemistry and gallstone formation in aged guinea pigs. Two groups of guinea pigs (1-mo and 3-y old; n=40 each) were studied. Each group was divided into four subgroups of 10 animals each; one subgroup received lithogenic diet, one each received CCK or erythromycin daily in addition to lithogenic diet for 4 weeks, and one received normal diet. After 4 weeks, the presence of gallstones or sludge was recorded and bile composition including concentrations of bile acid, cholesterol, lecithin and protein concentrations was studied. No gallstones were observed in the 1-mo-old animals. In the 3-year-old animals, 9 of 10 guinea pigs on lithogenic diet and 4 of 10 in each treatment subgroup and the normal diet subgroup developed gallstones. CCK and erythromycin had similar effects on bile chemistry and stone formation. Aging increases the formation of gallstones in guinea pigs. Erythromycin is as effective as CCK in reducing gallstone formation by improving gall bladder motility.
MeSH Terms
- Aging
- Animals
- Bile
- Bile Acids and Salts
- Cholelithiasis
- Cholesterol
- Cholesterol, Dietary
- Erythromycin
- Gallbladder Emptying
- Guinea Pigs
- Male
- Phosphatidylcholines
- Sincalide
Healthy aging is associated with reductions in appetite and food intake--the so-called anorexia of aging, which may predispose to protein-energy malnutrition. One possible cause of the anorexia of aging is an increased satiating effect of cholecystokinin (CCK). To investigate the impact of aging on the satiating effects of CCK, 12 young and 12 older healthy subjects received 25-min iv infusions of saline (control) and CCK-8, 1 ng/kg per min or 3 ng/k per min, on 3 separate days before a test meal. Older subjects ate less than young subjects, and food intake was suppressed 21.6% by CCK-8, compared with the control day (P < 0.05). The suppression of energy intake by CCK-8 in older subjects was twice that in young subjects (32 /- 6% vs. 16 /- 6% SEM, P < 0.05) and was related to plasma CCK-8 concentrations, which were higher at baseline (P < 0.05) and increased more during CCK-8 infusions in older than young subjects (P < 0.01). The extent of suppression of food intake per given rise in plasma CCK-8 concentrations did not differ between the two age groups (P = 0.35). Endogenous CCK concentrations were higher at baseline in older subjects (P < 0.001) and decreased during the CCK-8 but not control infusions (P < 0.01), suggesting that CCK suppresses its own release. Plasma leptin concentrations were not affected by CCK infusion, whereas postprandial insulin concentrations were lowered and the peak postprandial glucose concentration was delayed but not affected by CCK-8 infusion. Because older people retain their sensitivity to the satiating effects of exogenous CCK and plasma endogenous CCK concentrations are higher in older people, increased CCK activity may contribute to the anorexia of aging.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Anorexia
- Blood Glucose
- Cholecystokinin
- Eating
- Fasting
- Female
- Humans
- Hunger
- Injections, Intravenous
- Insulin
- Leptin
- Male
- Nausea
- Osmolar Concentration
- Satiety Response
- Sincalide
Previous studies have shown that sulfated cholecystokinin octapeptide (CCK-8S) can improve learning in adult rodents when administered systemically or into the central nucleus of amygdala. Here we analyzed the effect of repeated intraperitoneal (i.p.) injection of CCK-8S on the performance of 26-month-old Fischer 344 rats in different versions of the Morris water maze and in a rota-rod test of motor coordination. Old rats were injected daily with different doses of CCK-8S (0.32 to 8.0 microg/kg; IP) 10 min before the behavioral tests. Control groups included vehicle-injected old and adult (3-month-old) F 344 rats. To control for a possible development of tolerance to the behavioral effects of repeated CCK-8S administration, groups of aged rats were included which were subjected to an acute rather than a repeated CCK injection schedule. The repeated administration of CCK-8S did not influence the performance of the old rats in the hidden-platform version of the maze. In addition, the acute treatment with CCK-8S failed to modify navigation performance in this task, suggesting that drug-tolerance may not account for the lack of behavioral effects seen after repeated CCK-8S injection. During the "probe trial", the percentage of animals per group, which swam exactly across the former platform site, was markedly increased in aged rats treated repeatedly with 1.6 microg/kg CCK-8S. This might be indicative of improved retention of the prior platform location and/or a higher resistance of the learned escape response to extinction. The specificity of the effect of CCK-8S on processes related to spatial learning and memory is supported by the lack of effect on motor performance.
MeSH Terms
- Age Factors
- Aging
- Animals
- Cholecystokinin
- Male
- Maze Learning
- Peptides
- Rats
- Rats, Inbred F344
- Time Factors
- Water
We examined the effect of troglitazone treatment on pancreatic growth in the CCK-A receptor-deficient Otsuka Long-Evans Tokushima fatty (OLETF) rat, an animal model for type 2 diabetes mellitus. A troglitazone-rich diet (0.2%) was given from 12 to 28 wk of age or from 12 or 28 wk of age to 72 wk of age. Fasting serum glucose concentrations in control OLETF rats increased progressively with age, which was almost completely prevented by troglitazone treatment. Insulin levels in serum and pancreatic content in the control rat markedly increased at 28 wk of age but significantly decreased at 72 wk of age compared with those at 12 wk of age, whereas those in troglitazone-treated rats were nearly the same at all ages and were similar to those in control rats at 12 wk of age. Pancreatic wet weight in control rats decreased with age irrespective of whether they were hyperinsulinemic (28 wk old) or hypoinsulinemic (72 wk old). Troglitazone treatment significantly increased pancreatic wet weight and protein, DNA, and enzyme contents compared with those in the control rats. Moreover, troglitazone treatment completely prevented or reversed histological alterations such as fibrosis, fatty replacement, and inflammatory cell infiltration. Our results indicate that troglitazone stimulates pancreatic growth in the congenitally CCK-A receptor-deficient OLETF rat not only by reducing insulin resistance and potentiating insulin action but also by suppressing inflammatory changes in the pancreas.
MeSH Terms
- Aging
- Amylases
- Animals
- Blood Glucose
- Chromans
- Diabetes Mellitus, Type 2
- Fibrosis
- Homeostasis
- Hyperinsulinism
- Hypoglycemic Agents
- Insulin
- Insulin Resistance
- Lipase
- Male
- Pancreas
- Rats
- Rats, Inbred OLETF
- Receptor, Cholecystokinin A
- Receptors, Cholecystokinin
- Reference Values
- Thiazoles
- Thiazolidinediones
- Troglitazone
- Trypsin
The existence of a functional connection between the nervous and the immune system is supported by increasing recent evidence. In previous work we have shown that peptides from the nervous system, such as gastrin-releasing peptide (GRP), neuropeptide Y (NPY) and sulfated cholecystokinin octapeptide (CCK-8s), have modulatory effects on the immune functions in adult animals. Since the immunodepression found in aging organisms may be related to changes in the neuroimmune network, the aim of the present work was to study the changes with aging in the effect of CCK-8s, GRP and NPY on peritoneal macrophage functions (adherence to tissues, mobility, ingestion of foreign particles and superoxide anion production) from BALB/c mice of three different ages: adult (24 /-2 weeks old), mature (50 /-2 weeks old) and old (72 /-2 weeks old). The results show that the increase in adherence capacity produced by neuropeptides in cells from adult and mature animals disappears in old mice. The stimulatory effect of GRP and NPY on mobility, ingestion and superoxide production in macrophages from adult mice disappears (GRP) or changes to inhibition (NPY) in cells from old animals. The decrease of these functions caused by CCK-8s in adult or mature animals continues in old mice. These data suggest that the modulation by neuropeptides of the macrophage function changes with the age of animals.
MeSH Terms
- Aging
- Animals
- Cell Adhesion
- Cells, Cultured
- Chemotaxis, Leukocyte
- Gastrin-Releasing Peptide
- Macrophages, Peritoneal
- Male
- Mice
- Mice, Inbred BALB C
- Neuropeptide Y
- Nootropic Agents
- Phagocytosis
- Sincalide
- Superoxides
Cholecystokinin (CCK) and gastrin exert their effects through two receptors, the CCK-A and CCK-B receptors. We have cloned the mouse CCK-B receptor gene (Cckbr) and determined its complete genomic structure, nucleotide sequence, and tissue-specific expression pattern. Cckbr is divided into five exons spanning 11 kb. A primer extension assay was used to map the transcription initiation site to 199 bp upstream of the translational start site. Rapid amplification of cDNA ends was used to localize the 3' end downstream of an atypical polyadenylation site (GATAAA). Mouse Cckbr transcripts were most abundant in brain and stomach, but were also detected in colon, kidney, ovary, and pancreas. Prenatal expression of both CCK-A and CCK-B receptors in various tissues was analyzed by RT-PCR. The expression pattern was similar to the adult pattern, suggesting that receptor transcription is an early event in gastrointestinal development.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Base Sequence
- Cloning, Molecular
- Embryo, Mammalian
- Exons
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Introns
- Mice
- Molecular Sequence Data
- Organ Specificity
- RNA, Messenger
- Receptor, Cholecystokinin A
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
We recently found that, compared with younger healthy subjects, older healthy subjects had less symptomatic and cardiovascular response to the panicogenic agent cholecystokinin tetrapeptide (CCK-4). As an exploratory part of that study, we also evaluated the effect of aging on neurohormonal responses to CCK-4. These hormonal data are the focus of this article. Forty healthy volunteers aged 20-35 years and 40 healthy volunteers aged 65-81 years, divided equally between men and women, were compared on their hormonal responses (maximum change from baseline in growth hormone [GH], prolactin, adrenocorticotropic hormone [ACTH], and cortisol) to the intravenous administration of 50 microg of CCK-4 or placebo. Blood samples for serum hormone determination were collected at 2 minutes prior to the intravenous challenge (baseline) and at 2, 5, and 10 minutes after the challenge. In both age groups, maximum increase in prolactin, ACTH and cortisol was significantly greater with CCK-4 than with placebo. Following administration of CCK-4, younger and older groups did not significantly differ in maximum increase in prolactin, ACTH, or cortisol. Older subjects had a statistically significant smaller increase in GH compared with younger subjects but the magnitude of the difference was small and of doubtful clinical relevance. Older subjects who had a panic attack had significantly greater elevations of all hormones compared with those who did not panic and younger panickers had a significantly greater elevation of GH compared with young nonpanickers. For the most part, maximum changes in hormonal levels were not correlated with symptom severity, suggesting that other factors may have contributed to the differential effect of panic on the HPA axis.
MeSH Terms
- Adrenocorticotropic Hormone
- Adult
- Aged
- Aged, 80 and over
- Aging
- Double-Blind Method
- Female
- Human Growth Hormone
- Humans
- Hydrocortisone
- Male
- Panic Disorder
- Placebos
- Prolactin
- Tetragastrin
Three-month-old female Wistar rats were fed with 20% alcohol in their drinking fluid over 6-17 mo using an interrupted feeding regimen. At different times, pancreatic acini were isolated by mild collagenase digestion. The concentrations of inositol-1,4,5-trisphosphate (1,4,5-IP3) were determined by a specific radioreceptor assay, before and at different times after stimulation with varying concentrations of CCK-8. CCK-induced dynamics of cytoplasmic calcium ([Ca2 ]c) was investigated in acinar cells by confocal laser raster microscopy. Acinar alpha-amylase (Aml) secretion was measured as enzyme activity in the medium compared to the total activity in the suspension. In 12-13-mo-old rats, the CCK-stimulated 1,4,5-IP3 formation in acini was found to be decreased compared to young rats (age 4 mo). In rats of the same age fed with ethanol from the age of 3 mo on, 1,4,5-IP3 concentrations in acini were higher and reached values comparable to those in young rats. Correspondingly, the CCK-induced [Ca2 ]c dynamics in acini isolated from 9-mo-old rats was impaired compared to that of young rats but normal in aged, chronically alcohol-fed rats. Aml secretion under CCK stimulation, however, which was decreased in aged rats, was additionally impaired after alcohol feeding. Chronic alcohol feeding modifies 1,4,5-IP3 formation, the [Ca2 ]c dynamics of, and the Aml secretion of rat pancreatic acini in response to CCK stimulation. Obviously, the age-related impairment of 1,4,5-IP3 formation and [Ca2 ]c dynamics is improved. In contrast, the decrease in Aml secretion of acini isolated from aged rats is more pronounced after long-term alcohol-feeding.
MeSH Terms
- Aging
- Alcoholism
- Animals
- Calcium Signaling
- Cytoplasm
- Female
- In Vitro Techniques
- Inositol 1,4,5-Trisphosphate
- Pancreas
- Rats
- Rats, Wistar
- Sincalide
- alpha-Amylases
The effects of age on cholecystokinin (CCK) release, pancreatic enzyme secretion, and growth of the pancreas mediated by dietary kidney beans or soya beans were evaluated in trials with 30-, 90-, 250-, and 400-day-old rats. Soya beans increased blood CCK and caused hypersecretion of digestive enzymes and rapid pancreatic growth in all rats. Kidney beans also elevated circulating CCK and stimulated enzyme secretion. However, with 90-, 250-, and 400-day-old rats, the secretory responses were attenuated. Furthermore, kidney beans did not induce pancreatic growth in 250- and 400-day-old rats.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Chymotrypsinogen
- DNA
- Diet
- Fabaceae
- Intestines
- Male
- Organ Size
- Pancreas
- Phytohemagglutinins
- Plant Lectins
- Plants, Medicinal
- Proteins
- RNA
- Rats
- Soybeans
- Trypsinogen
- alpha-Amylases
The frequency and distribution of 11 endocrine cell populations were studied in the intestine of differently aged buffalo, grouped on the basis of diet: 2-d-olds (suckling), 5-mo-olds (weaning) and 5-y-olds (ruminant adult diet). The endocrine cell populations were identified immunocytochemically using antisera against 5-hydroxytryptamine (5-HT), somatostatin, gastrin, cholecystokinin (CCK), COOH-terminal octapeptide of gastrin/CCK, neurotensin, motilin, gastric inhibitory polypeptide (GIP), secretin, glucagon/glicentin (GLU/GLI) and polypeptide YY (PYY). In adult buffalos the regional distribution of endocrine cells is similar to that of other adult ruminants. During postnatal development, these cell types showed the following changes in their frequency and distribution: (1) 5-HT, neurotensin and gastrin/CCK immunoreactive cells (i.c.) showed a decrease in frequency with age; (2) somatostatin i.c. frequency remained stable with age; (3) motilin, GIP, secretin and CCK i.c. showed a slight increase in frequency with age; (4) GLU/GLI and PYY i.c. decreased in frequency with age in the small intestine, caecum and proximal colon and an increase in frequency in the rectum. It was hypothesised that the endocrine cell types, whose presence and localisation is substantially stable in all examined ages, probably contain substances that are strictly necessary for intestinal function. In contrast the hormones contained in the cell populations that decreased with age, are probably involved in physiological needs during the milk and weaning diet or play a role in intestinal growth.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Biomarkers
- Buffaloes
- Cell Count
- Enteroendocrine Cells
- Immunohistochemistry
Brain-derived neurotrophic factor (BDNF) modulates neuropeptide levels in hippocampus and cortex of young adult rats. Neuropeptide levels are altered in some age-related disorders, such as Alzheimer's and Parkinson's Disease. BDNF may be able to rectify peptide abnormalities but, because plasticity decreases with age, BDNF may not alter peptide levels as readily in aged animals. To determine if BDNF would regulate peptide levels in aged rats, young, aged memory-impaired, and unimpaired rats were infused with BDNF or vehicle into hippocampus and cortex. Cell profile counts, cell profile areas, fiber counts, and/or fiber terminal densities were measured for sections immunostained for neuropeptide Y (NPY), somatostatin (SOM), cholecystokinin-8 (CCK), and dynorphin A(1-8) (DYN). Results showed that BDNF upregulated cortical NPY-immunoreactivity (ir) and SOM-ir, upregulated hippocampal NPY-ir, and downregulated hippocampal DYN-ir in both aged and young rats. In addition, BDNF significantly and selectively normalized the areas of atrophied deep cortical CCK-ir cell profiles in aged-impaired rats. Finally, decreased CCK-ir fiber density was found in the hippocampal formation of aged memory-impaired rats.
MeSH Terms
- Aging
- Animals
- Brain-Derived Neurotrophic Factor
- Cell Count
- Cerebral Cortex
- Cholecystokinin
- Dynorphins
- Hippocampus
- Immunohistochemistry
- Male
- Maze Learning
- Memory
- Nerve Fibers
- Neurons
- Neuropeptide Y
- Neuropeptides
- Rats
- Rats, Sprague-Dawley
- Somatostatin
Lipid delays gastric emptying, and aging is associated with changes in gastric motor function and transit. However, little is known about the effect of lipid on gastric emptying time in the elderly. To determine the effect of aging on lipid gastric emptying, we used electrical impedance tomography (EIT) to study gastric emptying of liquid meals with or without lipid in five young (23.0 /- 0.6 years, mean /- SEM) and six elderly (73.3 /- 1.6 years) healthy male volunteers. These subjects drank 400 ml of non-lipid soup (triglycerides, 0 g) or lipid soup (triglycerides, 24.6g) in liquid test meals. To study the effect of lipolysis in the stomach, a liquid test meal containing 240mg of lipase in the lipid soup was also administered. Plasma cholecystokinin (CCK) concentration was measured by specific radioimmunoassay before and 30 min after the ingestion of a test meal. The gastric emptying time of the lipid soup was longer in the elderly than in the young subjects, and the time was significantly longer for lipid soup than for nonlipid soup (P < 0.05) in both the young and elderly subjects. Gastric emptying time for non-lipid soup was not significantly different between the elderly and young subjects. The administration of lipase shortened the gastric emptying time for lipid in both the elderly and the young subjects. Basal CCK concentration was significantly higher in the elderly than in the young subjects. However, there was no relationship between gastric emptying time and plasma CCK concentration after the ingestion of a test meal in the subjects overall. In conclusion, the delaying effect of lipid on gastric emptying is increased in the elderly, and the administration of lipase accelerates the emptying of lipid from the stomach.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Cholecystokinin
- Electric Impedance
- Gastric Emptying
- Humans
- Lipase
- Lipid Metabolism
- Lipids
- Lipolysis
- Male
- Time Factors
- Tomography
Pancreatic exocrine function and bile secretion were examined in cholecystokinin (CCK)-B receptor gene-targeted mice and compared among different genotypes [i.e., CCK-B receptor gene: ( / ), wild-type; ( /-), heterozygous; and (-/-), homozygous deficient]. The histology and protein concentrations in the pancreas also were examined. Amylase release from the dispersed acini was examined in vitro by using the various doses of CCK-8, carbachol, and secretin. In vivo, the bile and pancreatic juice were collected, and the concentrations of amylase and bile acid were measured in anesthetized mice. The responses to CCK (100 pmol/kg) or acetyl-beta-methylcholine (500 nmol/kg) were examined. In vitro studies showed that the maximal effective concentrations of CCK-8 (10(-l0) M), carbachol (10(-5) M), and secretin (5 x 10(-7) M) were comparable for all genotypes. Fluid, amylase, and bile acid outputs in vivo also were comparable for all genotypes. Pancreatic wet weight and protein concentrations were not significantly different, and no abnormal findings were observed on histologic examination in any genotype. These results indicated that the CCK-B receptor has no role in pancreatic growth, exocrine secretion, or bile secretion in adult mice.
MeSH Terms
- Aging
- Amylases
- Animals
- Bile
- Carbachol
- Female
- Heterozygote
- Homozygote
- Mice
- Mice, Knockout
- Organ Size
- Pancreas
- Pancreatic Juice
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
- Secretin
- Sincalide
Little information is available on the expression of cholecystokinin (CCK) receptors in the human pancreas, especially in the developing pancreas. We evaluated expression patterns for the CCK receptors in human pancreas at three different ages: fetus, infant, and adult. Expressions of CCK-A and CCK-B receptor messenger RNA (mRNA) were studied in human midtrimester fetus (14-15 weeks' gestation), infant (50 days old), and adult pancreas by reverse transcription-polymerase chain reaction (RT-PCR) followed by Southern blot analysis. Expression levels of mRNA for both receptors also were evaluated by Northern blot analysis of adult pancreas. Northern blot analysis showed a strong signal for CCK-B receptor mRNA in adult pancreas, but no detectable signal for CCK-A receptor mRNA. However, RT-PCR/Southern blotting showed the presence of CCK-A receptor mRNA in adult pancreas. This was confirmed by sequencing of the complementary DNA (cDNA). RT-PCR/Southern blot analysis also showed CCK-A and CCK-B receptor mRNA expression in fetal and infant pancreas. These results show that the both CCK receptor types are expressed in human pancreas at stages of early gestation, but there is predominant expression of CCK-B receptor in adult pancreas.
MeSH Terms
- Adult
- Aging
- Fetus
- Gene Expression Regulation, Developmental
- Gestational Age
- Humans
- Infant
- Pancreas
- RNA, Messenger
- Receptor, Cholecystokinin A
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic
Motility and secretory disorders of the gastrointestinal tract and associated glands increase with ageing. The duodenum contains several peptide/amine producing cells that play an important role in regulating gastrointestinal motility and secretion. The present study was performed to elucidate changes in these cells that may have arisen as a result of ageing. A total of four age groups of subjects, aged 1-2, 20-29, 40-49 and 60-69 years were studied. The various endocrine cell types were identified by immunohistochemistry and quantified by computerized image analysis, and two parameters were determined; the number of cells/mm3 epithelial cells and the cell secretory index (CSI), which indicates the immunoreactive secretory granule content of the endocrine cells. Chromogranin A- and serotonin-immunoreactive (IR) cells were fewer in 1-2-year-olds than in 20-29-year-olds. Gastrin/CCK-IR cells were significantly more numerous in 1-2-year-olds and 60-69 years-olds than in 20-29-year-olds. Somatostatin-IR cells were more numerous in the 40-49-year-olds than in the 20-29 years-olds. The CSI was higher in chromogranin A-, gastric inhibitory polypeptide (GIP)-, somatostatin- and gastrin/CCK-IR cells in 1-2-year-olds than in 20-29-year-olds. There was no significant sex difference regarding the numbers and CSI of other endocrine cell types. This study established the absence of sex-related differences in all endocrine cell types investigated, regarding numbers and physiological activity. Age, on the other hand, was shown to be associated with changes in the numbers of CCK-, somatostatin- and serotonin-IR, which may have some bearing on the gastrointestinal disorders of the elderly.
MeSH Terms
- Adult
- Aged
- Aging
- Duodenum
- Endoscopy, Gastrointestinal
- Enteroendocrine Cells
- Female
- Humans
- Image Processing, Computer-Assisted
- Immunoenzyme Techniques
- Infant
- Male
- Middle Aged
Sleep disorders are a major, although often minimized and underdiagnosed, medical problem. Current therapy is based on the use of hypnotics, mainly benzodiazepines, which disrupt the sleep pattern often suppressing rapid-eye-movement (REM) sleep. Here, new types of pharmacological tools such as cholecystokinin (CCK) receptor antagonists are examined. In particular, since the awake-sleep rhythm is mainly altered in old age in humans, the influence of these compounds over REM and non-REM sleep has been studied in aged rats (21 months) vs. young rats (5 months) prepared for electroencephalographic (EEG) recordings. Basal EEG data indicated that REM and non-REM sleep was reduced in aged rats vs. young rats. GV-150013, a selective CCK-B receptor antagonist, was found to increase REM sleep, as well as non-REM sleep, and therefore total sleep (non-REM REM) mainly in aged rats. The dose-range of activity (0.5-60 micrograms/kg) together with the evidence that another CCK-B receptor antagonist, L-365,260 (5 micrograms/kg) increased, while devazepide (a CCK-A receptor antagonist; 20 micrograms/kg) decreased non-REM sleep and total sleep time, support the original hypothesis that the activity of GV-150013 on sleep progress through CCK-B receptors. Furthermore, no tolerance was detected after chronic treatments with GV-150013. In contrast, typical EEG modifications (decrease of REM) and the development of tolerance towards benzodiazepines were monitored following chronic treatment with triazolam (400 micrograms/kg). These results suggest that the CCKergic compounds studied are involved via a different mechanism of action than benzodiazepines in the modulation of the awake-sleep rhythm. A further observation is that the total sleep time recorded in aged rats after treatment with GV-150013 reached the value of the total sleep time of young untreated rats also prepared for EEG. Finally, this work suggests that CCK receptor antagonists, GV-150013 in particular, are more effective in aged resulting in an improvement of sleep quality towards that of young rats.
MeSH Terms
- Adamantane
- Aging
- Analysis of Variance
- Animals
- Electroencephalography
- GABA Modulators
- Male
- Phenylurea Compounds
- Rats
- Rats, Wistar
- Receptor, Cholecystokinin B
- Receptors, Cholecystokinin
- Sleep
- Triazolam
Aging is associated with a decrease in appetite and a slowing of gastric emptying. The gastrointestinal hormones cholecystokinin (CCK), glucagon-like peptide 1 (GLP-1), and peptide YY (PYY) may mediate these changes. We investigated whether aging influenced the secretion of CCK, GLP-1, and PYY and their effects on appetite and pyloric motility. Eight healthy older (65-80 y) and 7 younger (20-34 y) men received isoenergetic (12.1 kJ/min) intraduodenal infusions of lipid and glucose for 120 min on separate days. Plasma CCK, GLP-1, and PYY concentrations were measured. Plasma CCK concentrations were higher in older than in younger subjects (P = 0.004) as a result of higher baseline values (4.7 /-0.2 compared with 3.2 /-0.2 pmol/L; P < 0.0001) and a greater rise during lipid infusion (increase from baseline: 7.1 /-0.5 compared with 5.3 /-0.6 pmol/L; P = 0.048). Plasma GLP-1 and PYY concentrations were not significantly different between groups. The decrease in hunger during intraduodenal lipid infusion was inversely related to the increase in CCK, GLP-1, and PYY in younger but not older subjects. During intraduodenal lipid infusion, the increase in isolated pyloric pressure wave (IPPW) frequency was positively related to GLP-1 and PYY and the increase in IPPW amplitude was positively related to CCK in older but not younger subjects, whereas the increase in IPPW amplitude and pyloric tone was negatively related to GLP-1 and PYY in younger subjects. Human aging is associated with increased CCK concentrations, which may contribute to the slowing of gastric emptying, mediated by increased pyloric motility. The role of increased plasma CCK concentrations in mediating the age-related decrease in appetite remains to be established.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Appetite
- Cholecystokinin
- Duodenum
- Fats
- Gastric Emptying
- Glucagon
- Glucagon-Like Peptide 1
- Glucose
- Humans
- Male
- Peptide Fragments
- Peptide YY
- Protein Precursors
Several investigations have suggested that the interactions between the nervous and immune systems are modified with age. The aim of the present work was to study the effect of three neuropeptides: gastrin-releasing peptide (GRP), neuropeptide Y (NPY) and sulfated cholecystokinin octapeptide (CCK-8 s) on natural killer (NK) activity of spleen, thymus and axillary node leukocytes from BALB/c male, young (8 /-1 weeks), adult (24 /-2 weeks) and old (72 /-2 weeks) mice. We used cells from murine lymphoma YAC-1 as targets for the cytotoxic assay and three physiological concentrations of the neuropeptides (10(-8), 10(-10) and 10(-12) M). In control samples, in the absence of neuropeptide, we observed a decreased NK activity in young and old mice with respect to the adults in the three organs studied. Regarding the effect of the neuropeptides, GRP stimulates the cytotoxic activity of leukocytes from all locations, in adult animals. At the same age, NPY also stimulates the NK activity of leukocytes from axillary nodes and thymus, whereas it decreases the NK activity of spleen leukocytes from young mice. CCK-8 s has an inhibitory effect on the axillary node leukocytes from young mice and spleen leukocytes from old animals. However, CCK-8 s increased the NK activity of thymus leukocytes from young and adult mice. The results indicate that the highest values of NK activity are found in adult mice, and that the stimulating effect of the three neuropeptides studied on NK activity of leukocytes from adult mice are reduced or disappeared, in general, in old as well as in young animals. Furthermore, the changes observed with ageing in the modulation of NK activity by the neuropeptides studied suggest an altered integration of the nervous and immune systems.
MeSH Terms
- Aging
- Animals
- Gastrin-Releasing Peptide
- In Vitro Techniques
- Killer Cells, Natural
- Leukocytes
- Lymph Nodes
- Male
- Mice
- Mice, Inbred BALB C
- Neuropeptide Y
- Sincalide
- Spleen
- Stimulation, Chemical
- Thymus Gland
The general immunodepression found in ageing organisms may be related to changes in the neuroimmune network. In the present study, the migration capacity of lymphocytes from BALB/c mice of three different ages: young (12 /- 2 weeks), adult (24 /- 2 weeks) and old (72 /- 2 weeks), has been assayed in vitro in response to three neuropeptides: sulfated cholecystokinin octapeptide (CCK-8s), gastrin-releasing peptide (GRP) and neuropeptide Y (NPY) in a physiological range of concentrations (10(-8)-10(-12) M). The capacity of migration to a chemical gradient or chemotaxis was studied by the Boyden's technique using f-met-leu-phe at 10(-8) M as chemoattractant. The results show a different response of lymphocytes to the different neuropeptides, as wells as to age, concentrations and locations studied. However, some similarities were found, for instance the three neuropeptides inhibited chemotaxis in thymus. The stimulatory effects that GRP and NPY exerted in young and adult mice were not observed in old animals. CCK-8s inhibited the chemotaxis in every organ studied, with the effect being more striking in old mice. Our conclusion is that stimulatory effects of the neuropeptides disappear or become inhibitory with ageing.
MeSH Terms
- Aging
- Animals
- Chemotaxis, Leukocyte
- Gastrin-Releasing Peptide
- Male
- Mice
- Mice, Inbred BALB C
- Neuropeptide Y
- Receptors, Cholecystokinin
- Sincalide
- T-Lymphocytes
Unlike adult antral cells, feline newborn antral cells are unable to contract in response to agonists in the absence of extracellular calcium or in response to exogenous inositol 1,4,5-triphosphate (IP3) after permeabilization. Changes in intracellular pathways that are associated with these differences were examined. In adult and kitten antrum isolated smooth muscle cell contraction, levels of 1,2-diacylglycerol (DAG) and IP3 were assessed in response to cholecystokinin (CCK). CCK-induced contraction was transient in the adult and sustained in the kitten. U73122 blocked contraction in adult antral cells but not kitten antral cells. In adult antral tissue, CCK (10(-7) mol/L) caused an early transient increase in the level of DAG, whereas in the newborn antrum, CCK (10(-7) mol/L) caused a sustained increase in the DAG level for up to 4 minutes. IP3 showed an early increase in both age groups. Newborn contraction is associated with an initial increase in IP3 and sustained elevation of DAG levels, whereas in adult antral cells, there is a transient increase in both IP3 and DAG. The relative inaccessibility of intracellular calcium stores in the newborn is associated with age-related differences in signal transduction pathways.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Calcium
- Cats
- Cell Movement
- Cholecystokinin
- Diglycerides
- Drug Interactions
- Estrenes
- Female
- Inositol 1,4,5-Trisphosphate
- Male
- Muscle Contraction
- Muscle, Smooth
- Phosphodiesterase Inhibitors
- Protein Synthesis Inhibitors
- Pyloric Antrum
- Pyrrolidinones
- Signal Transduction
- Time Factors
Cholecystokinin (CCK) is an important bioactive peptide which stimulates pancreatic enzyme secretion and is also a neuromodulator in the central nervous system. We examined whether CCK release from the central and peripheral tissues was decreased in old animals, and whether there were sex-related differences. Young (5-10-month-old) and old (25-29-month-old) male and female Wistar rats were used. Synaptosomes were prepared from the cerebral cortex, and the vascularly perfused duodenojejunum was isolated to examine central and peripheral CCK release, respectively. In some young female rats, 21 days after bilateral ovariectomy, the peripheral CCK release and the changes in CCK mRNA levels were examined. The central CCK release was impaired in response to the higher concentration of KCl, and the peripheral CCK response to the highest dose of neuromedin C was impaired in old male rats. However, no aging effect was observed in female rats, and ovariectomy did not affect CCK release or CCK mRNA level. CCK release from both central and peripheral tissues was decreased in old male rats, but not in old female rats.
MeSH Terms
- Aging
- Animals
- Bombesin
- Cerebral Cortex
- Cholecystokinin
- Duodenum
- Female
- In Vitro Techniques
- Jejunum
- Male
- Ovariectomy
- Peptide Fragments
- RNA, Messenger
- Rats
- Rats, Wistar
- Sex Characteristics
- Synaptosomes
The effect of intravenously administered ceruletide, a cholecystokinin (CCK) analogue, on neurophysiologic signs of stimulus processing was tested in 16 young (19-28 years) and 16 aged (70-86 years) healthy subjects. Placebo or 2.5 micrograms ceruletide was infused within 30 minutes according to a double-blind within-subject crossover design. Thereafter, auditory event-related brain potential (AERP) responses to stimuli of an "oddball" task (including the random presentation of frequent standard tones and rare target tones) were recorded. Amplitudes of the P2, P3, and SW components of the AERP were reduced in aged subjects (p < 0.05, p < 0.001, and p < 0.01, respectively), and latencies (from stimulus onset) of the N2 and P3 components were prolonged (p < 0.05 and p < 0.01, respectively). Together, these changes indicate impaired cognitive processing capabilities in aged compared with young subjects. Ceruletide enhanced P3 and also the subsequent slow-wave (SW) component that occurs 500 to 700 ms poststimulus in young subjects (p < 0.05 and p < 0.001, respectively). The peptide did not at all affect AERPs in the elderly subjects. Results demonstrate the capability of ceruletide after systemic administration to enhance central nervous system indicators of cognitive processing such as P3 and SW in young subjects. However, despite the clear effect of the CCK analogue in young subjects, it remained ineffective in the group of aged subjects and, thus, failed to compensate for the decline in AERP signs of working memory functioning in the elderly subjects.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Blood Pressure
- Ceruletide
- Cognition
- Cross-Over Studies
- Double-Blind Method
- Electroencephalography
- Evoked Potentials, Auditory
- Female
- Humans
- Injections, Intravenous
- Male
- Nootropic Agents
- Reaction Time
The effects of CCK on food intake were investigated under fixed feeding conditions in comparison to a test meal taken after 16 h of food deprivation. The experiments were performed on young adult rats (8 weeks old) as well on aged rats (23 months old). Intraperitoneal CCK-8 (8 and 40 micrograms/kg) significantly reduced the size of a test meal following 16-h food deprivation. This effect was independent of the age of the rats. However, under fixed feeding conditions neither of the doses used in this study reduced food intake in the young adult rats, whereas the highest dose of 40 micrograms/kg did so in the aged rats. These results suggest that the hypophagic effect of exogenous CCK-8 depends on experimental conditions, food intake being reduced after a period of food deprivation but not under a fixed feeding regimen in adult animals. Furthermore, the data suggest that age is a factor contributing to the complex behavioral actions of CCK, because only old animals were more susceptible to an anorectic action of CCK under the fixed feeding schedule. An explanation may lie in an interaction of other known behavioral effects of CCK (e.g., anxiogenic, mnemonic action) with its effects under the different feeding schedules.
MeSH Terms
- Aging
- Animals
- Appetite Depressants
- Dose-Response Relationship, Drug
- Eating
- Food Deprivation
- Male
- Rats
- Rats, Wistar
- Sincalide
1. Haloperidol increased the Met-enk level in the striatum at all age groups. However, the Met-enk level was decreased in AL of young and middle-aged rats by the drug. 2. Haloperidol elevated the beta-end level in AL and CCK level in NIL in young rats only. 3. The SP content in NIL was decreased by haloperidol in all age groups. 4. With regard to the effect of aging, Met-enk level in AL of middle-aged rats was higher than that in young rats. The beta-end level in AL also increased in old rats. 5. Aging modified the haloperidol effect on beta-end level in AL and CCK level in NIL as the effect was only observed in young rats. 6. In addition, aging caused a blunted response of Met-enk level to haloperidol in the striatum but an increased response of SP content to haloperidol in the NIL.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Corpus Striatum
- Enkephalin, Methionine
- Haloperidol
- Hypothalamus
- Male
- Pituitary Gland
- Radioimmunoassay
- Rats
- Rats, Sprague-Dawley
- Substance P
- beta-Endorphin
This work extends a recent observation that Otsuka Long-Evans Tokushima Fatty (OLETF) rats, which have been established as an animal model of non-insulin-dependent diabetes mellitus, show no expression of the cholecystokinin (CCK)-A receptor gene in the pancreas. The CCK-A receptor is known to be involved in regulating pancreatic exocrine function and growth. We examined the growth of the pancreas in terms of wet weight, enzyme compositions, and protein and DNA contents at 5-6 and 24-25 weeks of age in OLETF rats and control (Long-Evans Tokushima; LETO) rats. The pancreatic wet weight increased significantly with age in both OLETF and LETO rats but was significantly lower in OLETF rats than in LETO rats. The total DNA contents in the whole pancreas (cell numbers) were comparable for both strains and increased significantly with age. However, the ratio of protein content to DNA content (the cell size) significantly increased with age in LETO rats, with no increase in OLETF rats. The changes in chymotrypsin, amylase, and insulin with respect to age were in the same direction in both strains: a decrease or no change in total and/or cellular contents of chymotrypsin and insulin and increases in amylase. These results suggest that the CCK-A receptor plays some role in the increase in cell size associated with normal growth of the pancreas from 5 to 25 weeks of age (after weaning).
MeSH Terms
- Aging
- Amylases
- Animals
- Chymotrypsin
- DNA
- Insulin
- Organ Size
- Pancreas
- Rats
- Rats, Mutant Strains
- Receptor, Cholecystokinin A
- Receptors, Cholecystokinin
- Weaning
Sprague-Dawley rats develop progressive motor dysfunctions during the third year of life. We use this as a model to examine possible neuronal mechanism(s) that may cause motor impairments occuring during aging. In this study we have used indirect immunofluorescence histochemistry (IF) and in situ hybridization histochemistry (ISH) to study quantitatively and qualitatively the staining pattern and mRNA expression of calcitonin gene-related peptide (alpha-CGRP), growth-associated protein 43 (GAP-43), and acidic fibroblast growth factor (aFGF) in spinal lumbar motoneurons of young adult (2-3 months) and aged (30 months) Sprague-Dawley rats. In addition, mRNAs encoding choline acetyltransferase (ChAT), beta-CGRP, and cholecystokinin (CCK) were analyzed. All aged rats used in this study disclosed symptoms of hindlimb incapacity, ranging from mild weight-bearing insufficiency to paralysis of the hind limbs. The symptoms were confined to the musculature of the hindlimb and hip regions. Only a small number (approximately 15%) of the large motoneurons that innervate the hindlimb muscles were lost in those aged rats that had clinical symptoms of hindlimb motor incapacities. The remaining motoneurons expressed ChAT mRNA at levels similar to those of young adult rats. The vast majority of these motoneurons showed increased mRNA levels for alpha-CGRP and GAP-43. Aged motoneurons contained more CGRP like immunoreactivity (LI), but the number of immunoreactive neurons was smaller than in adult rats. GAP-43-LI could be detected in motoneurons in aged, but not in adult, rats. GAP-43-LI was always colocalized with CGRP-LI in aged motoneurons. Studies of individual aged rats revealed that the increase of GAP-43 mRNA-positive cell bodies occurred in cases with the most severe clinical symptoms, whereas the increase in alpha-CGRP was even evident in rats with mild symptoms. No alterations in content of aFGF-LI or aFGF mRNA could be detected in the aged rat, and the content of CCK and beta-CGRP mRNAs was also normal. The usefulness of this rat model for studies of neuromuscular aging and possible functional roles for GAP-43 and CGRP in plastic and regenerative processes during aging are discussed.
MeSH Terms
- Aging
- Animals
- Calcitonin Gene-Related Peptide
- Cell Count
- Cellular Senescence
- Cholecystokinin
- Choline O-Acetyltransferase
- Fibroblast Growth Factor 1
- GAP-43 Protein
- Growth Substances
- Hindlimb
- Lumbosacral Region
- Male
- Membrane Glycoproteins
- Motor Neurons
- Nerve Degeneration
- Nerve Tissue Proteins
- RNA, Messenger
- Rats
- Rats, Sprague-Dawley
- Spinal Cord
Cholecystokinin (CCK) is an abundant neurotransmitter peptide in the brain. CCK release from synaptosomes obtained from the cerebral cortex, the level of CCK mRNA and the tissue concentration of CCK were examined in young and old rats. CCK release stimulated by KCl was attenuated in old rats but that stimulated by calcium ionophore was comparable in animals at both ages. The CCK mRNA level in the cerebral cortex was decreased significantly in old rats despite the significant increase in CCK content. These results suggested that aging impaired CCK release, resulting in tissue accumulation and a decrease in the synthesis of CCK (the level of CCK mRNA).
MeSH Terms
- Age Factors
- Aging
- Animals
- Cerebral Cortex
- Cholecystokinin
- DNA, Complementary
- RNA, Messenger
- Rats
- Rats, Wistar
- Synaptosomes
To elucidate the hypothesis that gastrin and cholecystokinin (CCK) are local growth factors for colorectal mucosa, we have examined the peptide gene expression in rat colon during development. Northern analysis, reverse transcription PCR, and sequence-specific radioimmunoassays were the essential methods. High concentrations of gastrin and CCK messenger RNA were found in the fetal colon. At birth, gastrin and CCK mRNA's were both undetectable but increased subsequently towards adult life. The fetal colon contained 5.5 and 4.2 pmol/g tissue gastrin and CCK, respectively. After birth, carboxyamidated gastrin disappeared from the colon, whereas the concentration of CCK remained at 1 pmol/g. Glycine-extended gastrin and CCK were also present in the fetal colon, but towards adult life they decreased below 0.2 pmol/g. In contrast, progastrin and proCCK were detectable at all ages. Rat colon expresses the gastrin and CCK genes throughout life. The posttranslational maturation of progastrin, however, ceases shortly after birth, indicating that gastrin may play a role in the developing colon. Whether CCK influences the development remains to be shown.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Blotting, Northern
- Cholecystokinin
- Colon
- Female
- Fetus
- Gastrins
- Gene Expression Regulation
- Oligodeoxyribonucleotides
- Polymerase Chain Reaction
- Pregnancy
- Protein Precursors
- Protein Processing, Post-Translational
- RNA Probes
- RNA, Messenger
- Rats
- Rats, Wistar
- Transcription, Genetic
The prototypical brain/gut peptide cholecystokinin (CCK) has been used to assess brain and gut repair kinetics following cytotoxic injury in the rat. Studies addressed the effect of repetitive injury as well as aging. Injury was induced by one of the two alkylating agents, one active in the brain, the other systematically. Consistently the responses differ between brain and intestine. Total RNA falls (as predicted) in the intestine (control 1.5 /- 1.4 versus cytotoxic 0.21 /- 0.06 tRNA mg/organ, P < or = 0.0001), but rises (unexpectedly) in the brain (control 0.79 /- 0.04 versus cytotoxic 1.02 /- 0.03 tRNA mg/organ, P < or = 0.001). CCK mRNA concentration falls in the brain (predicted) (control 27 /- 1 versus cytotoxic 11 /- 1 pg CCK mRNA/micrograms tRNA, P < or = 0.001), but rises in the intestine (unexpectedly) (control 0.18 /- 0.02 versus cytotoxic 0.3 /- 0.04 pg CCK mRNA/micrograms tRNA, P < or = 0.001). CCK peptides do not change in the brain (control 39 /- 4 versus cytotoxic 34 /- 4 nmol/g, P < or = NS), but rise (unexpectedly) in the intestine (control 43 /- 4 versus cytotoxic 250 /- 27 nmol/g, P < or = 0.001). We ascribe these observations to differing brain/gut cell turnover kinetics. These data indicate that a rebound phenomenon occurs during gut recovery from cytotoxic injury. We additionally show a differential age-related response to cytotoxic injury. Younger animals tolerated the injury better than old ones (mortality: young 27% (3/11) versus old 66% (8/12), P < or = 0.001). Additionally, intestinal recovery is more rapid in younger animals. These data suggest that with increasing age, chemotherapeutic dosages may need to be modulated. It is additionally possible that clinically applicable algorithms may be developed using our animal model.
MeSH Terms
- Aging
- Animals
- Brain
- Carmustine
- Cell Cycle
- Cholecystokinin
- DNA
- DNA Damage
- Intestinal Mucosa
- Intestines
- Mechlorethamine
- RNA, Messenger
- Radioimmunoassay
- Rats
- Rats, Sprague-Dawley
Gallbladder (GB) motility diminishes with aging. This study was performed to characterize mechanisms that are involved in changes in GB contractility that occur during aging. Cytoplasmic Ca2 concentrations ([Ca2 ]i) and the contractile force of guinea pig GB muscle strips were simultaneously measured using fura-2 and force-displacement transducers. The binding ability of the Ca2 channel antagonist and GB muscle compliance were also examined. The COOH-terminal octapeptide of cholecystokinin (CCK-8) evoked a dose-dependent increase in force and [Ca2 ]i. Changes of [Ca2 ]i and contractile force of muscle strips in response to CCK-8 were significantly greater in young (2 mo old) compared with mature and aged (12 and 24 mo old) guinea pigs (changes in [Ca2 ]i, ED50: 46.1 nM at 2 mo, 6.1 microM at 12 mo, and 2.8 mM at 24 mo; changes of contractile force, ED50: 24.8 microM at 2 mo, 2.1 mM at 12 mo, and 357 mM at 24 mo). However, the magnitude of the contraction at each percent change in [Ca2 ]i was actually similar in young and aged guinea pigs. In a Ca(2 )-free buffer, the responses of [Ca2 ]i and force to CCK-8 in both young and aged GB muscles decreased, but those were still dose and age dependent. Binding ability of the Ca2 channel antagonist did not differ in the young and aged groups, but the compliance of the GB muscle strip decreased with aging. These results suggest that both a reduced mobilization of intracellular Ca2 and a decreased muscle compliance are responsible, at least in part, for age-related reduced contraction of guinea pig GB in response to CCK.
MeSH Terms
- Aging
- Animals
- Calcium
- Calcium Channels
- Cell Membrane
- Cytoplasm
- Diltiazem
- Gallbladder
- Guinea Pigs
- In Vitro Techniques
- Isometric Contraction
- Kinetics
- Muscle Development
- Muscle, Smooth
- Sincalide
Cholecystokinin (CCK)/gastrin receptors were characterized in calf pancreatic plasma membranes from newborns, 28- and 119-day-old milk-fed preruminants, and 119-day-old weaned ruminants. Scatchard analysis of [125I]Bolton-Hunter reagent-[Thr28,Nle31]CCK-(25-33) binding indicated two classes of binding sites: high affinity sites exhibited significant higher affinity and binding capacity (P < 0.05) in 119-day-old ruminants than in 119-day-old preruminants (Kd = 0.13 /- 0.02 vs. 0.35 /- 0.08 nM; binding capacity (Bmax) = 53 /- 12 vs. 18 /- 5 fmol/mg protein). Pharmacological analysis using selective agonists and antagonists indicated the expression of the CCK-A receptor at birth, whereas the CCK-B receptor predominated at postnatal stages. At all stages, the binding was inhibited by guanosine 5'-[gamma-thio]triphosphate. Binding site identification by photoaffinity labeling showed that at birth, the labeling occurred mainly on a 78- to 96-kilodalton (kDa) component. In milk-fed animals, aged 28 and 119 days, two membrane-binding components were labeled at 78-96 and 43-52 kDa. In 119-day-old ruminants, labeling occurred mainly on a 40- to 47-kDa protein. Deglycosylation by endo-beta-N-acetylglucosaminidase-F of the 40- to 47- and 43- to 52-kDa components resulted in the formation of a 37-kDa membrane protein. Consequently, this study demonstrated 1) the differential expression of CCK-A and -B receptors in developing calf pancreas, 2) the predominance of CCK-B receptors in normal pancreas, and 3) the maturation of CCK-B receptors during the weaning period, which includes the glycosylation level. These results suggest that CCK may play a predominant role during the early postnatal development, while gastrin and CCK-B receptors can function progressively to regulate proliferation and exocrine secretion in the calf pancreas, especially from the weaning period.
MeSH Terms
- Affinity Labels
- Aging
- Animals
- Animals, Newborn
- Binding Sites
- Cattle
- Cell Membrane
- Cholecystokinin
- GTP-Binding Proteins
- Gastrins
- Glycosylation
- Indicators and Reagents
- Kinetics
- Pancreas
- Peptide Fragments
- Photochemistry
- Receptors, Cholecystokinin
- Succinimides
Biliary tract disease is particularly prevalent in older persons, and is the leading indication for acute abdominal surgery in the elderly. The complications of biliary stone disease are more insidious in the elderly, and the recognition of "symptomatic" disease is often delayed. The unreliable manifestations of biliary tract pathology result in a higher morbidity and mortality of the disease, and a large number of emergency operations. Recent studies suggest that the pathophysiology of cholelithiasis is specifically altered in the elderly. Pigmented gallstones, which are more common in the elderly, are thought to result from the action of bacterial enzymes that deconjugate bilirubin and form insoluble bile salts; bacterial contamination of the extrahepatic biliary system is more frequent in elderly patients. Gallbladder stasis may be due to age-related changes in the response of gallbladder musculature to the kinetic action of cholecystokin (CCK), possibly through a decrease in CCK receptor affinity or availability. Other hormonal factors which inhibit choleresis, such as pancreatic polypeptide, are increased with aging as well. Current efforts are being directed toward closer surveillance and discovery of cholelithiasis, and improved outcomes of therapy have been aided by the development of "minimally invasive" approaches to the treatment of cholelithiasis in the elderly.
MeSH Terms
- Adolescent
- Adult
- Aged
- Aging
- Cholelithiasis
- Female
- Gallbladder
- Humans
- Male
- Middle Aged
- Postoperative Complications
The central distribution of neurons activated to express cFos immunoreactivity in response to peripheral administration of cholecystokinin octapeptide (CCK) was examined in 2-day-old rats. Similar to previous results in adult rats, neurons in specific subregions of the area postrema and nucleus of the solitary tract (NST) expressed cFos after CCK treatment. However, in marked contrast to results in adult rats, CCK treatment in neonates did not stimulate cFos expression in hypothalamic neurons or in other forebrain areas, and did not increase plasma oxytocin levels. These results suggest that vagal sensory activation of intrinsic brainstem circuits may be sufficient for the known inhibitory effects of exogenous CCK on gastric motility and feeding in neonatal rats. The prominent forebrain activation produced by CCK administration in adult rats likely reflects later maturation of direct and relayed ascending neural projections from the NST.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Cholecystokinin
- Female
- Hypothalamus
- Male
- Medulla Oblongata
- Neurons
- Proto-Oncogene Proteins c-fos
- Rats
- Tissue Distribution
Plasma secretin and cholecystokinin (CCK) levels and the periodic secretions of the exocrine pancreas were studied simultaneously with the duodenal migrating myoelectric complexes (MMC) in six milk-fed calves which had been starved overnight. The experiments were performed first when the calves were 10 to 16 days old and subsequently when they were 36 to 45 days old. Plasma secretin and the secretion of pancreatic juice fluctuated periodically in phase with the duodenal MMC: plasma secretin, and the pancreatic secretion of water and protein were significantly higher during the phase of irregular spiking activity than during the phase of no spiking activity in both investigations. Plasma CCK did not change throughout the MMC. The intravenous infusion of secretin at 120 pmol kg-1 bodyweight for one hour markedly stimulated pancreatic secretion and prolonged the duodenal MMC cycle, but it did not abolish pancreatic and duodenal periodic activity.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Cattle
- Cholecystokinin
- Duodenum
- Male
- Muscle, Smooth
- Myoelectric Complex, Migrating
- Pancreatic Juice
- Secretin
The laminar distribution and the density of cholecystokinin-like (CCK) neurons in the developing visual cortical areas (17, 18 and 18 a) were studied in Wistar rats that were reared under normal lighting conditions or in complete darkness. Immunocytochemistry on paraffin sections at postnatal days (P) 7, 14, 21, 30 and 60 showed that the density of CCK neurons in all visual areas of both groups of animals progressively increases from P7 to P21 but declines thereafter, to reach 50-75% of peak densities at P30. From P30 to P60 the density of CCK neurons in the visual cortex remains relatively unchanged in non-deprived animals, but increases slightly again in areas 17 and 18 a of dark reared rats. Fluctuations in the density of CCK neurons reflect changes in the number of immunoreactive neurons mainly present in layers IV-VI. It is concluded that the development of the CCK neurons in the rat visual cortex is minimally affected by light deprivation.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Darkness
- Immunohistochemistry
- Neurons
- Rats
- Rats, Wistar
- Reference Values
- Visual Cortex
This study was undertaken to examine the effects of increasing doses of rat somatocrinin (GRF) with or without a somatostatin antiserum (SS-ab) on serum hormone and metabolic concentrations, as well as serum and duodenal cholecystokinin (CCK) and antral gastrin concentrations. 24-day-old male Sprague-Dawley rats were injected twice daily s.c. (10:00 and 16:30) for 14 consecutive days with either saline or rat GRF (1-43) NH2 (4 and 20 micrograms/kg) in gelatin. Three other groups of animals received the same treatment in association with the SS-ab given i.p. every other day making up the 6 groups of 12 animals in a 2 x 3 factorial design experiment. GRF treatment increased circulating growth hormone (GH) concentrations in a dose-dependent manner, alone or in combination with the SS-ab; the SS-ab treatment alone or combined with GRF also increased GH concentrations. Total hypophyseal GH content was increased (P < 0.05) by the GRF treatment alone. Serum levels of IGF-1, acetoacetate, alpha 2 globulin and antral gastrin were all increased by the GRF treatment with plateaus observed for antral gastrin and serum IGF-1 levels at the intermediary dose of GRF. Serum concentrations of T4 were reduced at the 4 micrograms/kg dose of GRF. Serum concentrations of CCK were increased by the SS-ab treatment alone, an effect reversed by increasing doses of GRF. Rat GRF produced a dose-dependent increase and decrease of alpha 2 globulin and albumin, respectively. These data indicate that GRF, probably via its effect on GH release, influences gastrointestinal hormone levels which are implicated in gastrointestinal organ growth and digestive processes.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Dose-Response Relationship, Drug
- Drug Interactions
- Gastrins
- Globins
- Growth Hormone
- Growth Hormone-Releasing Hormone
- Immune Sera
- Insulin-Like Growth Factor I
- Male
- Radioimmunoassay
- Rats
- Rats, Sprague-Dawley
- Somatostatin
- Thyroxine
The neuropeptide cholecystokinin (CCK) is involved in the regulation of female, but not male, reproductive behavior. In both sexes, estrogen regulates the expression of CCK in adulthood within the bed nucleus of the stria terminalis and medial amygdaloid nucleus. These areas are parts of an interconnected limbic system-hypothalamic circuit, the development of which is influenced by estrogen during the early postnatal period. This is the same period during which central nervous system (CNS) expression of CCK is dramatically increased, suggesting that the male and female patterns of CCK expression may be the result of early postnatal exposure to estrogen. In the present experiment, the expression of preprocholecystokinin (pCCK) mRNA was determined by in situ hybridization with an isotopically labeled pCCK complementary RNA and emulsion autoradiography in animals whose neonatal and adult gonadal steroid levels had been manipulated. The number of pCCK-expressing cells in animals that were gonadectomized as adults was determined by neonatal estrogen, but stimulation with steroids in adulthood induced a similar number of pCCK-expressing cells in both sexes in the medial amygdala and bed nucleus of the stria terminalis. Neonatal treatment of females with estrogen or testosterone, followed by ovariectomy in adulthood, eliminated the sex difference in pCCK mRNA expression. Males treated neonatally with the aromatase inhibitor androstenedione (to block metabolism of testosterone to estrogen) and orchidectomized in adulthood had a level of pCCK mRNA expression that was similar to that of ovariectomized females. These data suggest that, during neonatal development, estrogen determines the constitutive expression of pCCK mRNA in the medial amygdala and bed nucleus of the stria terminalis, resulting in higher levels of pCCK mRNA expression in males than in females. However, exogenous gonadal steroids induce the same levels of pCCK mRNA expression in adult females, indicating that the levels of gonadal steroids and the patterns of their secretion are the predominant influences on the sexually dimorphic adult levels of pCCK mRNA expression.
MeSH Terms
- Aging
- Amygdala
- Animals
- Animals, Newborn
- Autoradiography
- Cholecystokinin
- Female
- Gonadal Steroid Hormones
- Hypothalamus
- In Situ Hybridization
- Limbic System
- Male
- Orchiectomy
- Ovariectomy
- Pons
- Protein Precursors
- RNA Probes
- RNA, Messenger
- Rats
- Sex Characteristics
Morphological features of the endocrine cells in the duct system of the pancreas and the biliary tract have been recently characterized in the adult animal with respect to their physiological roles. In the present study, we have investigated their chronological appearance as well as their developmental progress at various stages of the rat fetal and postnatal life. On day 12 of gestation, glucagon and insulin, as well as CCK cells, were identified in the pancreatic primordium. On day 14, glucagon and CCK cells were first detected in the epithelial lining of the common hepatic and the hepatic ducts. These cells remained the dominant endocrine type in the duct system during the fetal period. Insulin and pancreatic polypeptide cells were first observed in the common hepatic duct only on days 16 and 18 of gestation respectively. In spite of their presence in the islets, somatostatin cells were not detected in the duct system during fetal life. They started to appear in the accessory pancreatic duct of the neonate, and subsequently in the common hepatic duct as well as in the small pancreatic ones on day 7 after birth. During postnatal development, the endocrine cells showed progressive or retrogressive changes in different portions of the duct system according to the cell type. In general, somatostatin, CCK and pancreatic polypeptide cells showed an increase, while glucagon and insulin cells gradually dwindled in number up to the adult stage. Somatostatin cells exhibited a significant increase in number, becoming the highest population among the duct endocrine cells in the adult. Throughout the developmental progress, the endocrine cells appear to be allocated in regions relevant to their possible influence modulating the exocrine secretion as well as the drainage of the pancreatic and bile fluid.
MeSH Terms
- Aging
- Animals
- Bile Ducts
- Cell Division
- Cholecystokinin
- Gastrointestinal Hormones
- Glucagon
- Immunohistochemistry
- Insulin
- Pancreatic Ducts
- Pancreatic Hormones
- Pancreatic Polypeptide
- Rats
- Rats, Sprague-Dawley
- Somatostatin
Plasma and cerebrospinal fluid (CSF) concentrations of three well-known satiety neuropeptides, cholecystokinin (CCK), somatostatin and calcitonin gene-related peptide (CGRP), along with two powerful orexigenic neuropeptides, neuropeptide Y (NPY) and beta-endorphin have been measured in elderly persons with idiopathic anorexia and normal weight healthy subjects in a similar age range. Plasma and CSF immunoreactivity levels of the two main fractions of CCK (CCK8s and CCK33) after being separated by HPLC were measured by a radioimmunoassay (RIA) developed in our laboratory, whereas the other neuropeptides were assayed by commercially available RIA kits. Elderly underweight anorectic patients had significantly lower levels of beta-endorphin but increased concentrations of NPY in both plasma and CSF when compared to controls. In addition to significantly higher levels of CCK8s but not CCK33 in plasma, we found a trend to higher CSF concentrations of CCK8s and a positive correlation between the body mass index and either beta-endorphin (r = 0.58, P < 0.05) or CCK8s (r = 0.69, P < 0.01) concentrations in CSF in the anorectic group. CSF somatostatin concentrations were decreased significantly, but plasma somatostatin levels and plasma and CSF concentrations of CGRP were similar in senile anorectics and controls. Treatment of five anorectic patients with megestrol acetate, 480 mg daily for 6 months, reversed only the decrease in CSF beta-endorphin levels but did not normalize the body weight or the fat body mass. On the basis of our findings, we hypothesize that a decrease in CSF beta-endorphin concentration along with a rise in plasma levels of CCK8s might be accounted for the primary anorexia of aging.
MeSH Terms
- Aged
- Aged, 80 and over
- Aging
- Anorexia
- Calcitonin Gene-Related Peptide
- Cholecystokinin
- Female
- Humans
- Male
- Middle Aged
- Neuropeptide Y
- Neuropeptides
- Somatostatin
- beta-Endorphin
Quantitative in situ hybridization histochemistry was used to determine the age-related changes in tyrosine hydroxylase (TH) mRNA and cholecystokinin (CCK) mRNA in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the rat. Coronal sections (10 microns) were cut in a cryostat through the VTA and SNc of brains from 3 months and 33 month old Sprague-Dawley rats and immediately adjacent sections hybridized with 35S-labelled 45-mer oligonucleotide probes specific for either the rat TH or CCK genes. The mRNA levels of each gene were estimated by computerised densitometric analysis of the signal on X-ray film autoradiograms and estimation of the number of mRNA expressing cells as well as the density of expression per cell (grain density) was made from high resolution emulsion autoradiograms. Analysis of the TH mRNA on X-ray film autoradiograms indicated that the levels averaged 25% lower in the SNc (P < 0.01) and 18% lower in the VTA (P < 0.05) of the old rats. However, analysis of the emulsion autoradiograms showed that this reduction in TH mRNA in the VTA and SNc in the old rats was not due to a loss of TH mRNA expressing cells but due to a reduction in the hybridization signal per expressing cell.(ABSTRACT TRUNCATED AT 250 WORDS)
MeSH Terms
- Aging
- Animals
- Autoradiography
- Cholecystokinin
- Gene Expression
- In Situ Hybridization
- Male
- Oligonucleotide Probes
- RNA, Messenger
- Rats
- Rats, Sprague-Dawley
- Substantia Nigra
- Sulfur Radioisotopes
- Tyrosine 3-Monooxygenase
- Ventral Tegmental Area
The development of cholecystokinin satiety effects was studied in newborn rats. Weight gain during tests was the measure of intake in the sucklings, until the rats were weaned at 20 days of age. Thereafter food intake was measured directly. Intraperitoneal injection of cholecystokinin (CCK-OP) suppressed feeding in 1-7 day old rat pups. Gastric loads of 0.9% NaCl, 2.5% D-phenylalanine, and L-phenylalanine suppressed subsequent intake in 1-10 day old rats, but not in 10-20 day old rats. The early satiety effect of the intragastric loads was attributed to gastric distension. At 21-25 days of age, rats showed a suppression of intake following gastric loads of L-phenylalanine but not D-phenylalanine. This is tentative evidence that releasers of endogenous CCK do not induce satiety until immediately after weaning.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Body Weight
- Cholecystokinin
- Feeding Behavior
- Female
- Male
- Phenylalanine
- Rats
- Stereoisomerism
Immunoreactive cholecystokinin (iCCK), vasoactive intestinal peptide (iVIP) and secretin (iSEC) were determined in the brain and various gut regions in the developing rat between 3 and 28 days after birth and in the adult. From the different patterns observed with these three peptides, it is concluded that in rat neural tissues, peptide concentrations (iCCK in brain, iVIP in brain and gut) increase continuously until about 4 weeks. Concentrations in mucosal tissues (iSEC in gut) are equal to or higher than adult values 3 days after birth. Gut iCCK (found both in neuronal and mucosal tissues) peaks at about 2 weeks, presumably due to concentrations increasing in the former and decreasing in the latter tissues.
MeSH Terms
- Aging
- Animals
- Brain
- Brain Chemistry
- Cholecystokinin
- Digestive System
- Gastrointestinal Hormones
- Radioimmunoassay
- Rats
- Rats, Inbred Strains
- Secretin
- Vasoactive Intestinal Peptide
Modification of tyrosine residues of proteins has attracted great interest. Although phosphorylation has received most attention, tyrosine-O-sulphation is also common and has been closely investigated in the hormones gastrin and cholecystokinin (CCK). CCK regulates pancreatic enzyme secretion. It is always sulphated and sulphation increases its pancreatic secretagogue activity 100-fold. By contrast, only half of gastrin molecules are tyrosine-O-sulphated and sulphation does not influence the ability of gastrin to regulate gastric acid secretion. We now report that in neonatal rat pancreas, which is the major source of gastrin in the newborn rat, gastrin is completely sulphated. Moreover, the disappearance of gastrin from the pancreas during the first weeks after birth parallels the appearance of CCK in the intestine. Since sulphation is essential for pancreatic secretagogue activity of gastrin as well as of CCK, pancreatic gastrin in the neonate may be the equivalent of intestinal CCK in the adult.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Fetus
- Gastrins
- Intestine, Small
- Pancreas
- Rats
- Sulfuric Acids
- Tyrosine
This paper presents new information about inhibitory effects of intravenous injections of cholecystokinin-octapeptide (CCK-8) on feeding activity in birds, with particular reference to variation in motivational state. With increasing food deprivation (0, 1, 2 or 3 h) before injection, doses of 2 and 8 micrograms/kg CCK-8 became progressively less effective in suppressing feeding of domestic fowls. As with mammals, latency to feed was shorter, and subsequent feeding activity greater, with deprived than with undeprived birds. Fowls of broiler (meat-type) and layer strains, which have different absolute food requirements but similar relative (per kg body weight) requirements, did not differ in their feeding responses to injections of 1, 8 and 16 micrograms/kg CCK-8. Food intake of fowls fed on a diet diluted with 40% powdered cellulose was suppressed less by the same three doses of CCK-8 than that of birds fed on undiluted food. This may have been because birds with the more bulky diluted food had to spend a greater proportion of time feeding. Broiler chicks aged 2 and 6 weeks, which may have different blood-brain resistance to circulating CCK and which have different relative food requirements, did not differ in their feeding responses to injections of 2 and 8 micrograms/kg CCK-8. These results do not satisfy one of the criteria proposed for demonstrating the action of a satiety agent, that feeding should be suppressed in a consistent manner regardless of motivational state. An alternative explanation for the apparent satiating properties of CCK-8 is suggested, based on similarities in their time-course, and dependence on deprivation level, to abnormal gastrointestinal responses with similar doses of the peptide.
MeSH Terms
- Aging
- Animals
- Chickens
- Cholecystokinin
- Diet
- Feeding Behavior
- Female
- Food Deprivation
- Injections, Intravenous
- Species Specificity
- Time Factors
Motilin-like immunoreactivity (MLI) was determined in cerebelli and pituitaries of the rat from 4 days before birth to about 6 months after. Cholecystokinin (CCK)-like immunoreactivity was measured in the same pituitary samples for comparison. MLI concentration was highest 4 days prenatally in both tissues, while total tissue MLI content was higher after birth. Cerebellar MLI content was maximal from day 14 to 40, while pituitary MLI content increased gradually with age, roughly paralleling the increase in tissue protein. Pituitary CCK was detectable only postnatally; its concentration was maximal between days 19 and 29, and decreased substantially in older animals. The presence of detectable MLI in pituitary before birth is consistent with the observation that MLI can be visualized by immunocytochemistry in anterior pituitary somatotrophic cells, which are known to be active producers of growth hormone before and after birth. The presence of MLI before birth in cerebellum is consistent with the localization of MLI in Purkinje neurons, known to be formed before birth. The presence of MLI in the cerebellum before birth and its marked increase in content during the period of synaptogenesis are suggestive of a possible role of motilin in development.
MeSH Terms
- Aging
- Animals
- Cerebellum
- Cholecystokinin
- Gastrointestinal Hormones
- Motilin
- Pituitary Gland
- Radioimmunoassay
- Rats
The postnatal ontogeny of cholecystokinin receptors and cholecystokinin was determined in rat brain. The binding of cholecystokinin (CCK) to rat forebrain receptors was very low at 1-2 days of age, rose to a maximum at 12 days (Bmax = 31 fmol/mg protein, Kd = 1.47 nM), and declined to adult levels by 26 days (Bmax = 17 fmol/mg protein, Kd = 1.39 nM). In contrast, forebrain concentrations of CCK measured by radioimmunoassay rose monotonically through day 27. Possible implications of the transient developmental peak of CCK receptors are discussed.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Brain
- Cholecystokinin
- Female
- Kinetics
- Male
- Rats
- Receptors, Cell Surface
- Receptors, Cholecystokinin
The concentrations and hormonal forms of CCK and VIP have been determined in extracts of the brain and duodenum of the developing and adult pig. In methanol extracts of the brain cortex, the single hormone form, CCK8, increased from 130 /- 20 (Mean /- SEM) pmol/g at birth to an adult level of 300 /- 50 pmol/g. In acid extracts of brain, the predominant immunoreactive form had N-terminal immunoreactivity and increased from 240 /- 20 pmol/g at birth to an adult level 490 /- 30 pmol/g; the C-terminal immunoreactivity was about 10-fold lower. The concentrations and hormonal forms of immunoreactive CCK in duodenal extracts did not appear to be age-related. C-terminal immunoreactivity in methanol extracts averaged 140 /- 20 pmol/g and in acid extracts 240 /- 60 pmol/g. The concentration of N-terminal immunoreactivity in acid extracts averaged 490 /- 70 pmol/g. The VIP concentrations in acid extracts of the brain cortex was 13.5 /- 2 pmol/g at birth and rose gradually to 30 /- 9 pmol/g in the adult; in duodenal extracts it was 240 /- 18 pmol/g at birth and 195 /- 38 pmol/g in the adult. These results are in marked contrast with the ontogeny of these hormones in the rat in which brain concentrations of CCK and VIP in the neonate are less than 10% of adult levels and in which there are age-related changes in the content of these hormones in the duodenum as well.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Cerebral Cortex
- Cholecystokinin
- Duodenum
- Radioimmunoassay
- Sincalide
- Swine
- Vasoactive Intestinal Peptide
The objective of this study was to examine the effect of aging on gallbladder contraction and cholecystokinin (CCK) release, as well as on the correlation between the two in humans who are free of gallbladder disease. Twenty-nine human volunteers were divided into a young group of 14 individuals (ages 22 to 42 years, median age 32 years) and an older group of 15 individuals (ages 60 to 84 years, median age 66 years). In the study each person in both groups was given corn oil (Lipomul), 1.5 ml/kg, by mouth after an overnight fast. Blood was collected for measurement of CCK-33 by radioimmunoassay before and at intervals after ingestion of Lipomul. Simultaneous measurements of gallbladder volume were obtained by real-time varian ultrasonography. Both fasting and fat-stimulated concentrations of CCK in plasma were significantly higher in the older individuals than in the younger volunteers. The 60-minute integrated measurement of CCK release was significantly increased in the older people as compared with the young. Both fasting and maximally contracted gallbladder volumes were equal in the older and younger groups. The rate of emptying of the gallbladder was equal in both age groups, but the gallbladders of older people appeared to show an earlier initiation of contraction. The highly significant correlation of gallbladder contraction with levels of CCK was similar in both age groups, but the sensitivity of the gallbladder to CCK in the older people was significantly decreased. In conclusion, both fasting and fat-stimulated plasma levels of CCK increase with aging. The sensitivity of the gallbladder muscle to stimulation by CCK is diminished with age, but this appears, teleologically, to be matched by the increased release of CCK, so the kinetics of gallbladder emptying are little different in the aged.
MeSH Terms
- Adult
- Aged
- Aging
- Cholecystokinin
- Corn Oil
- Female
- Gallbladder
- Humans
- Kinetics
- Male
- Middle Aged
- Muscle Contraction
- Oils
- Ultrasonics
Cholecystokinin immunoreactive (CCKI) axons in the nucleus gracilis of the normal rat were studied by light and electron microscopy using the peroxidase-antiperoxidase (PAP) immunocytochemical method. Immunoreactivity was found in both normal and dystrophic axons at various ages. Slightly enlarged CCKI varicosities were first observed in 2-month-old rats, gradually increased in number (max. at 21 months) and in diameter (up to 20 micron at 21 months), and then decreased (at 27 and 36 months). Dilatated CCKI fibers continuous with dystrophic varicosities also tended to increase proportionally in diameter. The dystrophic CCKI axonal profiles, first identified at the light-microscopic level and then observed under electron microscopy, had consistently characteristic features. In addition, numerous dystrophic nonreactive axonal profiles had morphological features differing from those of dystrophic reactive ones at advanced ages. These findings suggest that CCK may be partly involved in the formation of dystrophic axons in the nucleus gracilis.
MeSH Terms
- Aging
- Animals
- Axons
- Brain Diseases
- Male
- Medulla Oblongata
- Microscopy, Electron
- Rats
- Rats, Inbred Strains
- Sincalide
Since the nucleotide sequence of cholecystokinin (CCK) cDNA was found in the rat gene, we applied cDNA to quantitate the CCK mRNA. The size of the mRNA for a CCK precursor was 850 nucleotides in length using brain cytoplasmic RNA. There were no bands except CCK mRNA by Northern blot analysis. We also examined the developmental changes and regional distribution of CCK mRNA in rat brains by dot-blot and gel-blot hybridization using CCK cDNA as a probe. CCK mRNA was barely detectable in the fetal brain, but started to increase postnatally and attained the plateau level after 20-30 days. Further, the level of CCK mRNA was highest in the frontal cortex, followed by those of the hippocampus and striatum. The cerebellum contained only negligible CCK mRNA. These results are in agreement with those of CCK concentration in the corresponding brain areas and suggest a transcriptional control of CCK concentration.
MeSH Terms
- Aging
- Animals
- Base Sequence
- Brain
- Cerebellum
- Cholecystokinin
- DNA
- Frontal Lobe
- Hippocampus
- Nucleic Acid Hybridization
- RNA, Messenger
- Rats
- Rats, Inbred Strains
We have developed a radioimmunoassay for the nonapeptide predicted by cDNA sequence analysis to reside at the extreme C-terminus of the mouse cholecystokinin (CCK) precursor. Sensitivity of the assay is 1 pg synthetic CCK precursor-related peptide (CCK-PRP)/ml. The antibody has no cross-reactivity with cholecystokinin, gastrin, or a variety of other known neuropeptides. We have employed this assay to demonstrate the presence, in rodent brain, gut, and peripheral plasma, of peptides with immunological properties that are identical to, and gel filtration characteristics that are very similar to, those of the synthetic CCK-PRP. We have also detected a similar peptide in the culture media of a human CCK-producing tumor. The molar ratios of immunoreactive CCK-PRP/CCK vary widely among tissues of origin and during ontogeny, suggesting regional and developmental differences in the turnover rates or in posttranslational modification of the two peptides. Our studies suggest that peptides very similar to intact CCK-PRP are posttranslationally liberated from the cholecystokinin precursor in a variety of tissues and may have neurotransmitter and/or hormonal functions distinct from those of CCK. Relatively high quantities of material immunologically indistinguishable from CCK-PRP were also found in several coelenterate species, indicating that this epitope arose as early in evolution as did CCK.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Antigen-Antibody Complex
- Brain
- Cholecystokinin
- Duodenum
- Gastric Mucosa
- Humans
- Immune Sera
- Invertebrates
- Mice
- Peptide Fragments
- Rats
- Rats, Inbred Strains
- Species Specificity
- Stomach
Changes in pancreatic exocrine function in young (6- and 12-month-old) and old (24- to 27-month-old) male Fischer (F-344) rats were examined. Rats were prepared with cannulae draining bile and pancreatic juice separately and with duodenal and right jugular vein cannulae. Experiments were conducted between the third and the seventh postoperative day in conscious rats. Bile and pancreatic juice were returned to the intestine during both the recovery period and between experiments. Pancreatic responses to endogenous [bile-pancreatic juice (BPJ) diversion from the intestine] and exogenous stimulation [0.086, 0.432, and 1.728 nmol/kg secretin and 0.033, 0.167, and 0.667 nmol/kg cholecystokinin-octapeptide (CCK-8)] were determined. Basal secretions of fluid, bicarbonate, and protein were not affected by aging. The pancreatic responses of fluid and bicarbonate secretion to BPJ diversion or secretin were unaffected by aging. However, the increment of protein secretion in response to BPJ diversion and the largest dose of CCK-8 was attenuated in old rats. It appears the duct cell function is hardly affected by aging, but that the reserve capacity for protein secretion in response to stimulation may decrease in old rats.
MeSH Terms
- Aging
- Animals
- Bicarbonates
- Bile
- Dose-Response Relationship, Drug
- Female
- Male
- Pancreas
- Pancreatic Juice
- Proteins
- Rats
- Rats, Inbred F344
- Secretin
- Sincalide
Early satiety may play a role in the anorexia of aging. The effects of the peripheral satiety agents cholecystokinin (CCK), bombesin, glucagon, and calcitonin were studied in 8 and 25 month old mice. During normal feeding behavior, the older mice consumed more than their younger counterparts, however, when food deprived, the younger consumed more. All peptides inhibited food intake over the first hour after administration in young and old mice. CCK, bombesin, and calcitonin suppressed feeding in 25 month old mice to a greater extent than in 8 month old mice. However, CCK demonstrated the greatest age-related suppression of food intake. CCK has a potential role to play in the pathogenesis of the anorexia of aging.
MeSH Terms
- Aging
- Animals
- Bombesin
- Calcitonin
- Cholecystokinin
- Circadian Rhythm
- Feeding Behavior
- Gastrointestinal Hormones
- Glucagon
- Male
- Mice
- Mice, Inbred C57BL
- Reference Values
Immunocytochemical localization of specific neurotransmitters in the brain is becoming increasingly important in studies of maturation. We have used the trilaminar prepyriform cortex (PC) of rats to study the distribution, patterns and relative number of cells, fibers and terminals during postnatal development using antisera to cholecystokinin (CCK) and glutamic acid decarboxylase (GAD). Both antisera show distinct patterns of immunoreactivity at birth and subsequent periods of distinct changes in these patterns. CCK immunoreactivity is rare but present at birth mostly in layer II. There is a dramatic increase of CCK-labeled structures between postnatal (PN) days 6 and 9 and between PN 13 and 21. The adult pattern is observed by PN 21 with large numbers of labeled cells in layer II, numerous terminals in layers II and deep I and large immunoreactive fibers in the lateral olfactory tract. At birth GAD-immunoreactive terminals are present mainly in layer I, forming a distinct pattern of superficial and deep bands. Subsequent major changes occur in this pattern between PN 9 and 13 and again between PN 13 and 21. By PN 21 there appears to be a loss in deeper laminae of GAD positive terminals which are possibly replaced by the increasing numbers of CCK terminals in the same sublaminae. The adult pattern of GAD immunoreactivity is established by PN 21 with terminals and a few cells in layer I. Therefore, throughout development of the rat PC, there is a distinct complementary and changing distribution of GAD and CCK. Factors that may influence these changes in immunoreactivity are discussed.
MeSH Terms
- Aging
- Animals
- Brain Chemistry
- Cholecystokinin
- Glutamate Decarboxylase
- Immunoenzyme Techniques
- Limbic System
- Methods
- Olfactory Pathways
- Rats
We have investigated the changes associated with development and aging on the interrelationships between cholecystokinin (CCK) and the pancreas in the guinea pig. Three groups (1 month old, 1 year old, and 3 years old) of male guinea pigs were sacrificed while feeding in order to measure food-stimulated levels of CCK in blood and in duodenal mucosa by radioimmunoassay (RIA), as well as the pancreatic concentrations of CCK receptors. Systemic blood concentrations of CCK did not change with age. However, the concentration and content of CCK in duodenal mucosa increased more than 3-fold with age. A single class of high-affinity (KD less than or equal to 0.1 nM) CCK-receptor was found on the pancreatic membranes. The concentration (fmol/mg protein) of these receptors significantly diminished by one-half with increasing age. We also found an apparently similar fall in the receptor-binding affinity, but the difference was not significant. We conclude that in the guinea pig, duodenal content of CCK increases so as to compensate for the decreasing concentration of pancreatic CCK receptors, or, perhaps, vice versa. The diminished exocrine function of the pancreas, seen with increasing age, may well reflect both the diminished number of CCK-receptors and the reduction of pancreatic acinar cells.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Duodenum
- Guinea Pigs
- Male
- Pancreas
- Receptors, Cholecystokinin
We have examined the effects of aging on guinea pig biliary motility both in vitro and in vivo. The first experiment compared contractile tension of gallbladder strips from young adult (6-12 months old) and 3-year-old guinea pigs in vitro. Contraction of gallbladder strips from the young guinea pigs was twice as forceful and was more sensitive to octapeptide of cholecystokinin (CCK-8) stimulation than the gallbladder strips from the older guinea pigs. The two groups were also studied in vivo by measuring changes in the intraluminal pressure of the gallbladder in response to exogenously administered doses of CCK-8. Young adult guinea pigs were more sensitive to CCK-8 at the lower doses tested and demonstrated gallbladder contractions that were more forceful than that of the old guinea pigs. CCK receptors were measured on gallbladder muscularis membranes from young adult and old guinea pigs. The number of receptors on gallbladder membranes decreased with age: 65.0 /- 17.7 fmoles/mg protein on membranes from 1 year old; 7.9 /- 2.0 fmoles/mg protein on membranes from 3 years old. The binding affinity of CCK receptors on gallbladder muscularis membranes for binding to CCK-8 was not significantly different in the two age groups studied. We conclude that age-related decreases in gallbladder responses to CCK-8 may be due to decreased concentrations of CCK receptors on gallbladder muscle cells.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Gallbladder
- Guinea Pigs
- Muscle Contraction
- Muscle, Smooth
- Receptors, Cholecystokinin
The postnatal development of cholecystokinin (CCK) binding sites in the rat forebrain and midbrain was studied by in vitro receptor autoradiography. In the majority of structures, the densities of sites were low over the first week after birth, increased until the third week, and decreased over the fourth week to reach adult levels. However, both the rate of increase and the extent of the decrease varied in large proportions among structures. For instance, labeling in the neocortex underwent its largest increase from postnatal day 10, while this increase was already begun at day 7 in the paleocortex. On the other hand, over the fourth postnatal week, the densities could either remain roughly constant (cingulate cortex), slightly decrease (thalamic reticular nucleus), or even return to background levels (pyramidal layer of hippocampus). These different timetables may depend mostly on the differential growth of cells expressing the CCK receptor gene within the developing CNS. The absence of CCK binding sites in most of the regions during the early postnatal period precludes a major role of this peptide in the embryonic development of the rat brain. However, in some regions as the ventromedial hypothalamic nucleus, the endopyriform cortex or the medial nucleus of amygdala, 30-50% of the adult levels were already present at birth. Whether this observation reflects an earlier functional maturation of these structures or a direct participation of the corresponding CCK systems in their development remains to be established.
MeSH Terms
- Aging
- Animals
- Autoradiography
- Brain
- Iodine Radioisotopes
- Mesencephalon
- Organ Specificity
- Rats
- Rats, Inbred Strains
- Receptors, Cholecystokinin
- Sincalide
The purpose of this study was to determine the ultrastructural basis for the immunoreactivity patterns in synaptic structures during development in layers I and II of the piriform cortex (PC) of rats. Antisera to cholecystokinin (CCK) and glutamic acid decarboxylase (GAD) were used at several different postnatal days (PN) and in adults to describe the distribution, characteristics, and relative frequency of labeled profiles--especially axons and terminals--with emphasis on details of the synaptic contacts. GAD-positive terminals occur from PN 2 to adulthood but only form contacts in deeper sublayers (Ib and II) initially. Contacts increase in layer I after PN 6 and are reduced in layer II after PN 21 when the GAD-labeled terminals and synapses take on adult features with flattened vesicles and symmetric contacts. CCK-labeled terminals are present in deeper sublayers at PN 2 but are few and rarely form contacts. Both terminals and contacts increase between PN 2 and 9, taking on distinctive shapes and vesicle morphology by PN 13. At PN 21 and older, CCK terminals have mainly flattened vesicles and mostly form symmetric contacts onto dendrites and somata in deeper layers (Ib and II). Superficial sublayer Ia has very few CCK-labeled synapses and axons. Thus immunoreactivity occurs in terminals prior to synapse formation; labeling of the presynaptic specializations precedes subsequent maturation; synaptic vesicle morphology and membrane specializations are similar for the vast majority of both CCK and GAD terminals; inhibitory (GABA) synapses are established sooner than the possibly excitatory CCK synapses; a deep to superficial gradient of synaptogenesis is associated with GAD-positive terminals in the PC; and the labeling patterns may be related to critical developmental or synaptogenic periods.
MeSH Terms
- Aging
- Animals
- Axons
- Cerebral Cortex
- Cholecystokinin
- Glutamate Decarboxylase
- Immunoenzyme Techniques
- Microscopy, Electron
- Rats
- Rats, Inbred Strains
- Synapses
Concentration of cholecystokinin-8 and the activity of glutamic acid decarboxylase were determined in the various cerebral cortical subdivisions of Japanese monkey (Macaca fuscata fuscata) at three different ages (embryonic 4 months, full-term and adult). The CCK-8 immunoreactive material extracted with 90% methanol from the cerebral cortex of the adult and foetal monkey were shown to be identical with synthetic cholecystokinin-8 by the criterion of co-elution on gel filtration chromatography (Sephadex G-50). The peptide concentration increased dramatically by about 30-80 fold (in terms of protein) and 17-28 fold (in terms of wet weight) between embryonic 4-month-old and full-term monkeys, while the level decreased 1/6-1/16 (protein) and 1/4-1/10 (wet weight) between full-term and adult monkeys. In adults, the highest levels of the peptide was observed in the association cortex, orbital prefrontal cortex and posterior parietal cortex. Glutamic acid decarboxylase activity, on the other hand, gradually increased about 4-10 fold (protein) between embryonic 4-month-old and adult animals and there was little variation in the increase rate among the cerebral subdivisions. In contrast to cholecystokinin-8, no reduction in the enzyme activity occurred between full-term and adult animals. The high level of cholecystokinin-8 in the embryonic period suggests that the peptide may participate in the regulation of the development of primate cerebral cortex.
MeSH Terms
- Aging
- Animals
- Cerebral Cortex
- Fetus
- Glutamate Decarboxylase
- Macaca
- Sincalide
The purpose of this study was to investigate in the aged animal the functional interaction between cholecystokinin (CCK) and amino acid neurotransmitter activity in the frontal cortex, a structure of importance in age-related disabilities. Guide cannula for repeated push-pull perfusion were implanted bilaterally in the superficial frontal cortex of male Sprague-Dawley rats. Two groups of animals were selected on the basis of their age at the time of stereotaxic surgery: 90 days and two years. Following post-operative recovery, an artificial CSF solution was perfused repeatedly within the cortex of each animal for a 5.0 min interval. The rate of perfusion was 25 microliters/min and a 5.0 min period elapsed between the collection of each sample of perfusate. After the initial control perfusions, CCK octapeptide was incorporated in a concentration of 6.0 or 18.0 ng/microliter in the CSF and perfused for 5.0 min under identical conditions. Each sample of perfusate was assayed by high performance liquid chromatography with electrochemical detection (HPLC-EC) for its content of glutamate (Glu), aspartate (Asp), glutamine (Gln), glycine (Gly), taurine (Tau) and gamma-amino-butyric acid (GABA) with homoserine used as an internal standard. Although CCK in the lower 6.0 ng/microliter concentration failed to alter significantly the profile of amino acids in the frontal cortex, the higher 18.0 ng/microliter solution of CCK enhanced the efflux of Glu as well as Asp, but only in the aged rats. Both concentrations of CCK tended also to augment the release of Gln in the older animals but these changes were not statistically significant. Both Gly and Tau were unaffected by CCK in either dose in both the young and old groups. GABA was not detectable in any of the samples of perfusate throughout the experiments. These results suggest that CCK-8 exerts a selective effect on amino acid neurotransmitter activity in the frontal cortex which is clearly age-dependent. In the older animal, this sensitivity of the cortical cells to CCK may reflect a functional attribute of the peptide in the aging process.
MeSH Terms
- Aging
- Amino Acids
- Animals
- Cerebral Cortex
- Cholecystokinin
- Male
- Neurotransmitter Agents
- Perfusion
- Rats
- Rats, Inbred Strains
Evidence has been presented for the existence of interactions between CCK and DA receptors both in striatal and limbic membranes. A similar type of modulation by CCK-8 of DA receptors also exists after chronic neuroleptic treatment indicating that supersensitive DA receptors are also modulated by this peptide. As seen from simulation curves, CCK-8 increases the binding of [3H]DA agonists and reduces the binding of [3H]DA antagonists in striatal membranes, suggesting that CCK-8 may increase striatal DA transmission. Results of this type may underlie some of the non-neuroleptic effects of CCK-8. In the aged brain, the ability of CCK-8 to modulate DA antagonist binding sites is changed such that the binding of [3H]DA antagonists is increased. Thus, in the aged brain, receptor-receptor interactions may be altered, leading to a derangement of heterostatic mechanisms (mechanisms changing chemical transmission without interfering with synaptic homeostasis). It was also demonstrated that during aging there is a preferential disappearance of CCK-like immunoreactivity versus TH immunoreactivity in the nigral DA neurons, especially in the medially located nigral DA cells; furthermore, co-existence in the TH/CCK co-storing terminals in the nucleus accumbens was reduced during aging. Such alterations should also lead to changes in heterostatic regulation because the CCK co-modulation line controlling the DA receptors may be preferentially affected.
MeSH Terms
- Aging
- Animals
- Apomorphine
- Brain
- Cholecystokinin
- Haloperidol
- Male
- Neurons
- Nucleus Accumbens
- Rats
- Rats, Inbred Strains
- Receptors, Dopamine
- Sincalide
- Tyrosine 3-Monooxygenase
Developmental changes of preprocholecystokinin mRNA (CCK mRNA) and cholecystokinin-like immunoreactivity (CCK-LI) were examined in rat brain regions (frontal cortex, colliculi, hippocampus, striatum, and cerebellum) using RNA dot blot assays with cholecystokinin (CCK) cDNA and radioimmunoassay, respectively. The CCK-LI levels in all regions examined were very low at birth. Excluding the cerebellum, the levels in these regions increased postnatally and reached adult values at 28 days of age. In contrast to CCK-LI, CCK mRNA levels changed dramatically during development. A considerable amount of CCK mRNA was detected in the frontal cortex and hippocampus at birth. The changes in the level of CCK mRNA in the frontal cortex and colliculi paralleled those of CCK-LI, including a rapid increase from 7 to 14 days of age. The synthesis of CCK mRNA preceded the appearance of CCK-LI. CCK mRNA levels in the hippocampus and striatum exhibited a transient increase, with a peak at 14 days of age. In the adult brain, the CCK mRNA levels were high in the frontal cortex, moderate in the hippocampus and colliculi, and low in the striatum. The cerebellum contained only a negligible amount of CCK mRNA during development. The relatively high level of CCK-LI compared with the low level of CCK mRNA in the striatum supports the idea that most of the striatal CCK-LI is supplied from extrastriatal regions.(ABSTRACT TRUNCATED AT 250 WORDS)
MeSH Terms
- Aging
- Animals
- Brain
- Cerebellum
- Cholecystokinin
- Corpus Striatum
- DNA Probes
- Frontal Lobe
- Hippocampus
- Nucleic Acid Hybridization
- RNA, Messenger
- Rats
- Rats, Inbred Strains
- Superior Colliculi
Differences in pancreatic responses and CCK release to intragastric administration of a synthetic protease inhibitor (camostate) were examined in young (6-mo) and old (26-mo) female rats. When rats were sacrificed 1 hour after camostate administration (100 mg/kg), plasma CCK concentration significantly increased in both age groups and was significantly higher in young rats than in the old. Acute pancreatic responses to camostate were attenuated in old rats, compared with the young. On the other hand, 5-day administration of camostate (100 mg/kg, twice a day) increased pancreatic wet weight, chymotrypsin concentration and content in pancreas in both age groups, whereas lipase content did not increase in old rats although it significantly increased in young rats. Plasma CCK concentrations were not significantly different between young and old rats. It is concluded that the acute response of CCK release to camostate is attenuated in old rats, but the capability of chronic pancreatic adaptation of chymotrypsin content to camostate is well maintained in old rats.
MeSH Terms
- Aging
- Animals
- Body Weight
- Cholecystokinin
- Dose-Response Relationship, Drug
- Female
- Gabexate
- Guanidines
- Intubation, Gastrointestinal
- Lipase
- Organ Size
- Pancreas
- Protease Inhibitors
- Rats
- Rats, Inbred F344
- Secretory Rate
- Trypsin
The rat has been a useful model for studying neuronal and metabolic abnormalities associated with fetal and neonatal hypothyroidism produced by treatment of the mother with antithyroid medication. The neonates are then maintained on this medication via the mother's milk until weaning and subsequently through the drinking water. We have determined the concentrations and contents of immunoreactive cholecystokinin (CCK) and vasoactive intestinal peptide (VIP) in the brain and gut of groups of rats exposed to antithyroid medication from day 16 of gestation. The neonates were sacrificed at 2, 4, 8 and 12 weeks. Compared to controls total body weight was greatly reduced in methimazole (MMI)-treated rats, all of whom were hypothyroid as evidenced by marked reduction of T4 and increase in TSH. Discontinuation of MMI-treatment after 8 weeks resulted in normalization of T4 and TSH and a dramatic weight gain but at 12 weeks the brain weights of the MMI-treated rats were reduced by 17% and the brain contents, of CCK and VIP were similarly reduced. Tissue weights throughout the gut were 1/2 or less than those of control rats. Since VIP but not CCK concentrations in the gut of MMI-treated animals were significantly greater than those of the control animals, it would appear that there was greater loss of mucosal tissue with its endocrine content of CCK than of neuronal tissue with its greater content of VIP.(ABSTRACT TRUNCATED AT 250 WORDS)
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Body Weight
- Brain Chemistry
- Cholecystokinin
- Digestive System
- Female
- Hypothyroidism
- Methimazole
- Organ Size
- Pregnancy
- Radioimmunoassay
- Rats
- Rats, Inbred Strains
- Vasoactive Intestinal Peptide
Basal pancreatic exocrine functions as well as responses to endogenous (BPJ diversion) and exogenous (injection of CCK-8 or secretin) stimulations were examined in young (6- and 12-month-old) and old (24- to 26-month old) female Fischer 344 rats. Basal secretions were not significantly different between young and old rats. BPJ diversion significantly stimulated pancreatic secretions of fluid, bicarbonate, and protein in all animals. The pancreatic protein response (mg/kg/hr) to BPJ diversion was significantly attenuated with respect to age [57.59 /- 16.16, 43.73 /- 6.94, and 20.75 /- 3.95, for 6-, 12-, 24- to 26-month-old rats, respectively, mean /- SE, F(2,20) = 3.49, P less than 0.05]. The pancreatic responses to secretin (0.086, 0.432, and 1.728 nmol/kg) were not significantly different between young and old rats. Intravenous injection of CCK-8 (0.033, 0.167, and 0.667 nmol/kg) produced a significant increase in protein output in all age groups. In young animals, stepwise increases in protein output were observed, whereas, in old rats, increments in response to the larger two doses of CCK-8 (0.167 and 0.667 nmol) were smaller than that produced by 0.033 nmol/kg of CCK-8. In conclusion, the basal secretions in old rats were comparable with those in young ones, but the reserve capacity for protein secretion appears to decrease in old compared to young rats.
MeSH Terms
- Aging
- Animals
- Bicarbonates
- Female
- Pancreas
- Pancreatic Juice
- Proteins
- Rats
- Rats, Inbred F344
- Secretin
- Sincalide
We examined the ontogeny of cholecystokinin (CCK) gene expression in the rat thalamus using hybridization histochemistry. Maturation of CCK gene expression occurred over the course of a month, beginning in the medial geniculate nucleus on the 17th day of gestation. CCK mRNA was found in the caudal nuclei first, later in the rostral; the ventral were followed by the dorsal; and the lateral by the medial. In some nuclei, such as the medial geniculate, CCK mRNA was present prior to the full differentiation of the neurons; whereas in others, such as the mediodorsal, the neurons differentiated to almost adult morphology before CCK mRNA was detected.
MeSH Terms
- Aging
- Animals
- Cholecystokinin
- Embryonic and Fetal Development
- Gene Expression Regulation
- Histocytochemistry
- Nucleic Acid Hybridization
- RNA, Messenger
- Rats
- Rats, Inbred Strains
- Thalamus
Animal studies have demonstrated that neuropeptides modulate nervous system functions. It has been postulated that disturbances in neuropeptide systems may be aetiological factors in psychiatric and neurological disorders. Neuropeptides related to ACTH/MSH, including ORG 2766, increase motivation and attention and facilitate recovery processes after nerve damage. These peptides may be effective during the early stage of dementia. Vasopressin and related peptides improve memory processes in animals and humans. In addition, these peptides influence social behaviour, mood and addictive behaviour. The non-opioid gamma-type endorphins have neuroleptic-like activities in animals and antipsychotic effects in a category of schizophrenic patients. Peptides related to CCK have also been found to be effective in these patients. Some neuropeptides, e.g. TRH and PLG, have been reported to exert antidepressant effects. Further research may eventually produce neuropeptides with therapeutic action in psychiatric and neurological diseases.
MeSH Terms
- Aging
- Animals
- Behavior, Animal
- Humans
- Memory Disorders
- Neuropeptides
- Psychotic Disorders
Although exogenous administration of cholecystokinin (CCK) or dietary manipulation to increase circulating CCK have previously been shown to promote pancreatic growth, the role of CCK in controlling normal pancreatic development remains unclear. A potent CCK receptor antagonist, L364,718, was administered to rats, guinea pigs, and hamsters to block the effect of endogenous CCK. Animals were given continuous infusions of L364,718 (25 nmol.kg-1.h-1), CCK octapeptide [(CCK-8) 200 pmol.kg-1.h-1], or both CCK-8 and L364,718 for 14 and 28 days. Adult (4-mo-old) and young (4-wk-old) animals were used. CCK-8 and L364,718 were administered via separate, subcutaneously implanted mini-osmotic pumps. Infusions of CCK-8 alone for 28 days resulted in a 21.7% increase in wet pancreatic weight in 4-wk-old rats and a 22.7% increase in 4-wk-old guinea pigs (both P less than 0.001 compared with controls). Similar increases were found in DNA, RNA, and total protein contents. Coadministration of L364,718 totally blocked the trophic effects of exogenously infused CCK-8 in rats and guinea pigs. Administration of L364,718 alone in hamsters, guinea pigs, and rats for 14 and 28 days failed to alter the normal growth of the pancreas gland as measured by these parameters. Although elevated levels of CCK appear to promote a potent trophic response in the growing pancreas, this regulatory peptide does not appear to be an essential trophic factor for the normal growth of the exocrine pancreas in these animals.
MeSH Terms
- Aging
- Animals
- Benzodiazepinones
- Cholecystokinin
- Cricetinae
- DNA
- Devazepide
- Female
- Guinea Pigs
- Male
- Mesocricetus
- Organ Size
- Pancreas
- Proteins
- RNA
- Rats
- Rats, Inbred Strains
- Receptors, Cholecystokinin
- Reference Values
- Sincalide
- Species Specificity
Amylase secretion by fetal and newborn rat pancreata was shown not to respond to cholecystokinin (CCK) stimulation. Binding of 125I-Bolton-Hunter (125I-BH)-CCK-8 to dispersed pancreatic acini from rats at various perinatal ages was measured and compared with adults. Binding occurred maximally at 30 min at 37 degrees C at all ages. Maximal binding increased with age. The capacity and affinity of the CCK-receptor binding system was analyzed by Scatchard's method. The results revealed that the capacity of the high-affinity component gradually increases with age, whereas that of the low-affinity component remains relatively constant. Amylase secretion due to CCK stimulation also increases with age, suggesting that the lack of responsiveness of pancreata of pups to secretagogue is due to a low binding capacity of the high-affinity component of the receptors.
MeSH Terms
- Aging
- Amylases
- Animals
- Bucladesine
- Calcimycin
- Carbachol
- Kinetics
- Pancreas
- Rats
- Rats, Inbred Strains
- Receptors, Cell Surface
- Receptors, Cholecystokinin
- Sincalide
Cholecystokinin (CCK) is a peripheral and central mediator of short-term satiety. When given i.p., CCK decreases food intake in previously fasted rats for a period of 30 min. The effect has been previously shown to be abolished by vagotomy and more specifically by severing of vagal sensory rootlets. These studies were designed to determine the effects on rat feeding behavior, and in particular CCK-satiety, of the sensory neurotoxin capsaicin. In neonates, capsaicin selectively and permanently destroys unmyelinated sensory fibers including those in the vagus nerve. Rat neonates were treated with capsaicin, 50 mg/kg or vehicle, and surviving females studied at 8-10 weeks of age. The weights, 24-h food intake, and feeding responses to insulin were the same in adult capsaicin treated (Cap Rx) and vehicle treated (Veh Rx) rats. CCK (8 micrograms/kg i.p.) reduced 30 min food intake 61 /- 18% in Veh Rx animals (mean /- S.D., P less than 0.01). In capsaicin denervated animals, CCK also significantly reduced 30 min food intake from 5.09 /- 1.10 to 3.92 /- 0.84 g (P less than 0.01), but the mean reduction, 23 /- 6%, was significantly less than in Veh Rx rats (P less than 10(-4]. A separate group of females, similarly treated as neonates with capsaicin or vehicle, were subjected to bilateral lesioning of the ventromedial hypothalamus. Both Cap Rx and Veh Rx animals gained significantly and equally more than non-lesioned controls. 24 h vagal transport of substance P was reduced 70% in age matched capsaicin treated animals compared to controls. These studies demonstrate that peripheral CCK-satiety is partly mediated by capsaicin sensitive fibers, presumably in the vagus nerve. Substance P is one possible transmitter mediating this reflex. Further conclusions are that active inhibition of an intact peripheral CCK-stimulated reflex arc is not necessary for full expression of central inducers of feeding, e.g., insulin or lesioning of the ventromedial hypothalamus, and that destruction of these fibers does not alter long-term weight regulation in rats receiving a normal diet.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Biological Transport
- Capsaicin
- Cholecystokinin
- Fasting
- Feeding Behavior
- Insulin
- Obesity
- Rats
- Rats, Inbred Strains
- Satiation
- Satiety Response
- Somatostatin
- Substance P
- Vagus Nerve
- Ventromedial Hypothalamic Nucleus
Using a library of radioimmunoassays for essential sequences of procholecystokinin (proCCK), we have examined the post-translational processing in the rat cerebral cortex from fetal to adult state. The concentration of proCCK in the fetal cerebral cortex was 43 /- 7 pmol/g tissue (wet weight; mean /- S.E.M. (n = 20)). It remained constant until day 21 post partum, after which it decreased to undetectable levels. In contrast, the concentration of fully processed, bioactive CCK peptides (i.e. alpha-carboxyamidated CCK) rose from 2 /- 1 pmol/g in the fetal cortex to 122 /- 21 pmol/g in the adult. A particularly steep increase occurred from day 7 post partum (13 /- 2 pmol/g) to day 21 (108 /- 11 pmol/g). The concentration of glycine-extended intermediates rose gradually from 8 /- 1 pmol/g in the fetal brain to 55 /- 6 pmol/g in the adult. Gel chromatography of cortical extracts from day 7, 21 and 100 confirmed the variable processing at the C-terminal amidation site. The results show that the CCK gene is expressed as proCCK already in the fetal brain. However, the covalent modifications of proCCK follow different time courses so that only a small fraction reaches maturation until the first week post partum. We conclude that expression of transmitter-active CCK peptides in the brain is largely regulated at the post-translational rather than at the transcriptional level.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal
- Cerebral Cortex
- Cholecystokinin
- Fetus
- Gene Expression Regulation
- Molecular Sequence Data
- Protein Precursors
- Protein Processing, Post-Translational
- Radioimmunoassay
- Rats
- Rats, Inbred Strains
Using the avidin-biotin-peroxide immunohistochemical method, we studied the distributions of somatostatin (SOM)-, cholecystokinin-8 (CCK-8)- and substance P (SP)-like immunoreactivities in the cerebellum of macaque monkeys at embryonic day 120 (E120), E140, newborn, postnatal day 60 (P60) and adults. During the embryonic stages, there were many SOM-, CCK- and SP-immunoreactive structures in the external granular layer, Purkinje cell layer and white matter, SP-immunoreactive mossy fibers and their terminals were distributed in the granular layer and white matter. During these stages, there were SOM-immunoreactive Purkinje cells, Golgi cells and a few cells in the molecular layer, and CCK-immunoreactive Purkinje cells and cells in the molecular layer. At the newborn stage, all of the immunoreactivities in the external granular layer decreased and the number of immunoreactive fibers increased in the white matter. At P60 stage, SOM- and CCK-immunoreactive fibers were observed around Purkinje cells, which seem to be the fiber terminals of basket cells. Many SOM, CCK and SP fibers were distributed in the white matter. In the adult stage, we observed little neuropeptide-immunoreactivity in the cerebellum. The high concentration of the neuropeptide-immunoreactive fibers and cells in the earlier stages suggests that the neuropeptides may be involved in the development of the primate cerebellar cortex.
MeSH Terms
- Aging
- Animals
- Cerebellum
- Embryonic and Fetal Development
- Female
- Immunohistochemistry
- Macaca
- Male
- Neuropeptides
HPLC-purified 125I-labeled vasoactive intestinal peptide (VIP) bound in a specific, saturable, and reversible manner to pancreatic plasma membranes isolated from newborn calves, from milk-fed calves at 28 and 119 days, and from weaned calves at 119 days. A series of VIP analogues, including pituitary adenylate cyclase-activating polypeptide (PACAP), displaced 125I-VIP binding and activated adenylate cyclase in the same order of relative potency: PACAP-38 greater than helodermin greater than VIP, PACAP-27 greater than PHM (human peptide with NH2-terminal histidine and COOH-terminal methionine amide). At maximally effective concentrations, these five peptides produced the same two- to threefold increase of adenylate cyclase activity in pancreatic membranes from newborn and 28-day-old calves, and fourfold in ruminant or preruminant animals at 119 days. The activation constant for PACAP-38 ranged from 0.1 to 0.34 nM throughout the postnatal development. Helospectin I and II were three times less potent than VIP in inhibiting 125I-VIP binding. At concentrations up to 0.1 microM, secretin, rat and human growth hormone-releasing factors, glucagon, oxyntomodulin, the truncated form of glucagon-like peptide-1 lacking the 6 NH2-terminal amino acid sequence (TGLP-1), GLP-2, gastric inhibitory peptide, gastrin, CCK, and insulin had no effect on binding. Scatchard plots from 28- and 119-day-old calves were compatible with the presence of two classes of 125I-VIP binding sites: one with a high affinity for VIP and a low binding capacity (Kd = 0.11-0.4 nM, Bmax = 66-174 fmol/mg protein) and the other with a low affinity and high binding capacity. At birth, only one class of binding sites was observed (Kd = 0.4 nM, Bmax = 858 fmol/mg protein). The covalently cross-linked PACAP-preferring 125I-VIP binding site is a glycoprotein of 55 kDa with higher sensitivity to PACAP vs. helodermin and VIP. Our results suggest that calf pancreatic functions might be regulated at an early stage of postnatal development by PACAP receptors linked to cAMP generation.
MeSH Terms
- Adenylyl Cyclases
- Affinity Labels
- Aging
- Animals
- Animals, Newborn
- Cattle
- Cell Membrane
- Chromatography, Affinity
- Enzyme Activation
- Kinetics
- Male
- Pancreas
- Receptors, Gastrointestinal Hormone
- Receptors, Vasoactive Intestinal Peptide
- Vasoactive Intestinal Peptide
Beta-endorphin (BE) and cholecystokinin (CCK) were measured in fresh PBMC isolated from human subjects and rats. The BE and CCK PBMC contents increased significantly with age both in human and rat models. Moreover, polyclonal stimulation induced a significant decrease of BE but not CCK contents in mononuclear cells from human aged subjects. The time course of changes in BE and CCK concentrations observed in fresh and cultured cells from subjects of different ages did not directly correlate to the time course of age-associated impairment of lectin-induced lymphocyte proliferative response and interleukin-2 synthesis. In fact, the lymphocyte functional defects were significantly observed only in the 71-99 year age group, whereas the neuropeptide changes were already evident in the 31-50 age group. Since BE has been shown to participate in the modulation of the immune system, the age-related modifications of PBMC BE could play a role in the immunodepression observed during aging.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Animals
- Cholecystokinin
- Humans
- In Vitro Techniques
- Interleukin-2
- Leukocytes, Mononuclear
- Lymphocyte Activation
- Male
- Middle Aged
- Rats
- beta-Endorphin
Pancreatic exocrine secretion was estimated in 180 normal control patients, free of abdominal and pancreatic disease, aged from 16 to 83 years. Duodenal juice was collected in two 15-min fractions after a single intravenous injection of 1 U/kg secretin 3 U/kg CCK. Volume, maximal concentration and output of bicarbonate, lipase, phospholipase and chymotrypsin were estimated as well as minimal concentration and output of chloride and calcium. Each parameter was plotted against age, either individually or after separation into two age groups. Volume linearly increased up to the 3rd decade, and thereafter linearly decreased. Bicarbonate secretion paralleled fluid secretion and also decreased after the 3rd decade. The changes in chloride and calcium concentrations were different: concentrations linearly increased after the 3rd decade. Calcium concentration linearly increased with age (p less than 0.02) while chloride output was unchanged. The three enzymes that were studied linearly decreased in concentration as well as in output with age from the 3rd decade (p less than 0.02). Protein secretion decreased before water and bicarbonate secretion. One can conclude that pancreatic secretion changes in humans with age. Aging alters pancreatic secretion, through a decrease in flow rate, bicarbonate and enzyme secretion while calcium concentration is enhanced. Although not requiring substitutive therapy in the whole population, individual cases of pancreatic exocrine insufficiency might be explained by aging, without malnutrition.
MeSH Terms
- Adult
- Aged
- Aged, 80 and over
- Aging
- Bicarbonates
- Chymotrypsin
- Female
- Humans
- Lipase
- Male
- Middle Aged
- Pancreas
- Pancreatic Juice
- Phospholipases
- Retrospective Studies
We have studied the anatomical distribution of cholecystokinin-like immunoreactive (CCK-IR) somata and fibers in the brain of the adult and developing Brazilian short-tailed opossum, Monodelphis domestica. Animals ranged in age from the day of birth (1PN) to young adulthood (180PN). A nickel enhanced, avidin-biotin, indirect immunohistochemical technique was used to identify CCK-IR structures. Somata containing CCK immunoreactivity were observed in the cerebral cortex, hippocampus, hypothalamus, thalamus, midbrain, and brainstem in the adult. Cholecystokinin immunoreactive fibers had a wide distribution in the adult Monodelphis brain. The only major region of the brain that did not contain CCK-IR fibers was the cerebellum. The earliest expression of CCK immunoreactivity was found in fibers in the dorsal brainstem of 5-day-old opossum pups. It is possible that the CCK-IR fibers in the brainstem at 5PN are of vagal origin. Cholecystokinin immunoreactive somata were observed in the brainstem on 10PN. The CCK-IR cell bodies observed in the brainstem at 10PN may mark the first expression of CCK-IR elements intrinsic to the brain. A broad spectrum of patterns of onset of CCK expression was observed in the opossum brain. The early occurrence and varied ontogenesis of CCK-IR structures indicates CCK may be involved in the function of a variety of circuits from the brainstem to the cerebral cortex. The early expression of CCK-IR structures in the dorsal brainstem suggests that CCK may modulate feeding behavior in the Monodelphis neonate. Cholecystokinin immunoreactivity in forebrain structures such as the suprachiasmatic nucleus, medial preoptic area, thalamus and cortical structures indicates that CCK may also be involved in circadian rhythmicity, reproductive functions, as well as the state of arousal of the Brazilian opossum. The ontogenic timing of CCK immunoreactivity in specific circuitry also indicates that CCK expression does not occur simultaneously throughout the brain. This pattern of CCK onset may relate to the temporal need for CCK in specific circuits of the central nervous system (CNS) during development.
MeSH Terms
- Aging
- Animals
- Brain
- Cholecystokinin
- Immunohistochemistry
- Nerve Fibers
- Opossums
- Tissue Distribution
The structural and functional properties of the pancreas are known to be affected by a number of hormones, particularly those of the gastrin-CCK family, yet little is known about the responsiveness of the pancreas to gastrin-CCK peptides during the latter stages of life. The present investigation examined the changes in pancreatic growth, the activity, and the steady-state mRNA levels of some of the digestive enzymes during advancing age and after administration of gastrin. Groups of 3-, 6-, 12-, and 16-month-old male Fischer-344 rats were infused (osmotic minipump) with either gastrin G-17 (250 ng/kg/h) or saline (controls) for 14 days. In control pancreas, aging resulted in slight progressive reduction in pancreatic DNA, RNA, and protein concentrations. This decrease was markedly enhanced by gastrin treatment in 16-month-old rats. Pancreatic amylase and trypsin (TRP) activities in these animals were also slightly decreased with aging, whereas the steady-state mRNA levels of both enzymes were significantly higher in 16-month-old rats than in their 3-month-old counterparts. However, in 16-month-old rats, the steady-state mRNA levels of amylase and TRP were significantly reduced after gastrin administration, when compared with the corresponding controls. Chymotrypsin (CHY) activity in the pancreas remained essentially unchanged between 3- and 12-month-old rats, but in 16-month-old animals it was markedly decreased. CHY activity was further reduced by gastrin treatment only in the 16-month-old group.(ABSTRACT TRUNCATED AT 250 WORDS)
MeSH Terms
- Aging
- Amylases
- Analysis of Variance
- Animals
- Body Weight
- Chymotrypsin
- DNA
- Gastrins
- Gene Expression Regulation, Enzymologic
- Male
- Organ Size
- Pancreas
- Pancreatin
- RNA
- RNA, Messenger
- Rats
- Rats, Inbred F344
- Trypsin
We examined the effect of age on the trophic response of the pancreas to chronic treatment with cholecystokinin (CCK), bombesin, or pentagastrin. Three age groups (3-, 12-, and 24-months) male F344 rats received saline; CCK-8 (5 ng/kg), bombesin (10 micrograms/kg), or pentagastrin (100 micrograms/kg) by intraperitoneal injection t.i.d. for 2 weeks. Rats were then killed and the pancreases excised, weighed, and assayed for DNA, RNA, protein, and polyamine (putrescine, spermidine, and spermine) concentrations and contents. We found that none of the treatments altered body weight at any age. All three hormones increased pancreas size and cell number in 3-month old rats, but by 12 months, all three had increased only pancreatic RNA content. Pancreatic spermidine concentration was decreased by all three hormone regimens in 3- but not in 12-month old rats, and pancreatic putrescine concentration and content were increased in 12-month old rats receiving all three hormones. There was no change in any parameter following any of the three hormones, tested at 24 months of age. We conclude that, at the dosages tested, the trophic response of pancreas to chronic administration of CCK, bombesin, and pentagastrin, which is normally present in young adult rats, is lost with aging.
MeSH Terms
- Aging
- Animals
- Bombesin
- Cholecystokinin
- DNA
- Dose-Response Relationship, Drug
- Injections, Intraperitoneal
- Male
- Organ Size
- Pancreas
- Pentagastrin
- Putrescine
- RNA
- Rats
- Rats, Inbred F344
- Rats, Inbred Strains
- Spermidine
Age related differential gene expression occurs in the neuro-enteral axis. Brain and gut organ weight, total RNA, total protein and three peptides were quantified in 4-, 10- and 37-week-old Sprague-Dawley rats. As animals aged, total RNA decreased in the brain (0.65 /- 0.3-0.28 /- 0.03 mg/g), but remained stable in the gut (2.6 /- 0.3-2.9 /- 0.4 mg/g). Total protein concentration rose in the duodenum (612 /- 28-734 /- 34 mg/g), while levels remained stable in the brain (641 /- 54-666 /- 34 mg/g). Three peptides were studied, cholecystokinin (CCK), VIP and secretin. With increasing age, significant changes were found only in CCK a true neural-enteral peptide. The concentration of smaller molecular forms of CCK decreased in the brain (248 /- 18-188 /- 21 pmol/g), while they remained stable in the duodenum (33 /- 2-36 /- 3 pmol/g). By contrast, the concentration of the larger forms of CCK were stable in the brain (36 /- 3-40 /- 4 pmol/g), but rose in the gut (89 /- 14-134 /- 17 pmol/g). These data indicate that as rats age there is preprogrammed differential control of gene expression between brain and intestine.
MeSH Terms
- Aging
- Animals
- Body Weight
- Brain
- Cholecystokinin
- Digestive System
- Gene Expression Regulation
- Male
- Organ Size
- Proteins
- RNA
- Rats
- Rats, Inbred Strains
Cholecystokinin (CCK) and benzodiazepine receptor binding characteristics were analyzed in the brain tissue samples from 19 suicide victims and 23 control cases. In the frontal cortex, significantly higher apparent number of CCK receptors and affinity constants were found in the series of suicide victims. These differences between suicides and controls were present in similar proportions when the suicide cases with depressive syndrome or violent or non-violent means of self-killing were compared to matched controls. However, when the samples were split into subgroups consisting of persons either below or over the age of 60 years, significant differences in the CCK receptor characteristics in the frontal cortex were observed only between younger suicides and controls. Furthermore, the younger suicide victims had a higher density of CCK receptors in the cingulate cortex, whereas in older suicides the value was lower as compared to age-matched controls. No difference in benzodiazepine receptor binding was found between control and suicide groups. The results of this investigation suggest that CCK-ergic neurotransmission is linked to self-destructive behaviour, probably through its impact on anxiety and adaptational deficits.
MeSH Terms
- Adolescent
- Adult
- Aged
- Aging
- Cerebral Cortex
- Female
- Frontal Lobe
- Humans
- Male
- Middle Aged
- Radioligand Assay
- Receptors, Cholecystokinin
- Suicide
The present account provides a developmental timetable for the maturation of cholecystokinin (CCK)-positive fibers in the cerebellar cortex and cerebellar nuclei of the opossum. CCK-positive fibers are in the cerebellar peduncle by postnatal day (PD) 1, however they wait until PD 7 to penetrate the cerebellar anlage. Between PD 7 and PD 20 the fibers wait again in the medullary core of the cerebellum. After PD 20, there are 2 distinct patterns of CCK localization within the overlying cortical layers. The first pattern develops between PD 20-26 when CCK puncta are present in restricted foci within the Purkinje cell layer of the anterior lobe vermis. They distribute in 4 parasagittal bands, 2 on either side of the midline, that extend from the primary fissure rostrally into the anterior lobe of the cerebellum. By PD 33 two additional parasagittal bands are present in the posterior lobe vermis. The vast majority of these CCK puncta are transient in nature as all but a few disappear by PD 84. Those that remain progress through a series of developmental stages characteristic of climbing fiber ontogeny. These climbing fibers persist in lobules V, VII and VIII of the adult cerebellum. Further, there is a transient expression of CCK-immunoreactivity within inferior olivary neurons. These observations support the interpretation that the transient population of CCK-IR puncta are immature climbing fiber axons derived from the inferior olive. The second pattern of CCK localization is evident between PD 30-33, the time when granule cells first can be recognized in a histologically distinct internal granule cell layer (IGL). Between PD 30 and PD 68 there is a differential pattern of distribution of CCK-IR profiles within the lobules of the cerebellum. Initially, CCK-IR axons are only present in the anterior vermis where they are aligned in register with the bands of CCK puncta in the Purkinje cell layer. CCK-IR puncta are not present in the posterior lobe vermis or hemispheres until later stages of development. Further, a sagittal organization is not evident in either of these latter 2 areas. Initially, CCK-IR profiles in the IGL cannot be identified as mossy fibers based on their terminal morphology. When they first enter the IGL they appear as punctate elements. Over time they become increasingly more complex in shape and between PD 68-84 develop morphological characteristics of adult mossy fiber rosettes. The cerebellar nuclei can be distinguished histologically by PD 18, but CCK-IR fibers are not evident among these neurons until PD 36 which corresponds to about the time they can be visualized in the IGL. In addition, CCK-IR cell bodies first appear in the cerebellar nuclei between PD 26-30; these are present in the adult.(ABSTRACT TRUNCATED AT 400 WORDS)
MeSH Terms
- Aging
- Animals
- Cerebellar Nuclei
- Cerebellum
- Cholecystokinin
- Immunohistochemistry
- Microscopy, Electron
- Neurons, Afferent
- Opossums
- Purkinje Cells
The cerebellum is the only region of the central nervous system which has been found to be devoid of cholecystokinin (CCK). The assays used, however, have been directed against the alpha-amidated C-terminus of fully processed CCK peptides. Using Northern blot analysis and a library of radioimmunoassays specific for different sequences of proCCK in combination with chromatography and enzyme cleavage, we have now examined the expression and processing of proCCK in fetal, neonatal and adult cerebellar tissue from man, pig and rat. In rat cerebellum CCK mRNA was present already in the fetal state. Two weeks after birth the concentrations declined. Also proCCK was found in significant concentrations in the fetal human and rat cerebellum (approximately 20 pmol/g); but already before birth the expression began to decrease towards low concentrations in adults. The adult porcine cerebellum contained 3.2 pmol proCCK and glycine-extended processing intermediates per gram (range less than 0.1-10.4 pmol/g), and 0.8 pmol carboxyamidated CCK per gram (range 0.1-4.1 pmol/g) varying in size from CCK-58 to CCK-5. For comparison, the adult porcine cerebral cortex contained 757 pmol carboxyamidated CCK/g, 20 pmol glycine-extended CCK/g and no proCCK. We conclude that cerebellum expresses proCCK with the highest level of expression in fetal life. In comparison with other regions of the brain, the maturation to transmitter-active, carboxyamidated CCK peptides is, however, attenuated in both fetal and adult cerebellar tissue.
MeSH Terms
- Aging
- Amino Acid Sequence
- Animals
- Animals, Newborn
- Cerebellum
- Cerebral Cortex
- Cholecystokinin
- Gestational Age
- Humans
- Molecular Sequence Data
- Protein Conformation
- Protein Precursors
- RNA, Messenger
- Rats
- Rats, Inbred Strains
- Sequence Homology, Nucleic Acid
1. The effects of age, weaning and feeding on the release of seven gut regulatory peptides [gastrin, cholecystokinin (CCK), secretin, vasoactive intestinal peptide (VIP), pancreatic polypeptide (PP), motilin and somatostatin] were studied in calves either exclusively milk-fed between birth and 91 days (P group) or weaned between 22-56 days of age (R group). 2. During the first 3 weeks, the basal plasma immunoreactive levels increased with age for secretin, CCK and PP, decreased for gastrin, motilin and somatostatin and were unaffected for VIP. The changes were particularly rapid for somatostatin and gastrin. After 3 weeks, no significant trend was observed with age in the P group. 3. Weaning resulted in an increase of basal gastrin, CCK, PP and VIP and in a decrease of basal secretin and somatostatin. 4. In the P group, the morning meal was followed 1 hr later by an increase of gastrin and CCK, and by a fall of secretin, PP, motilin and somatostatin, but no significant effect was observed in VIP. Weaning resulted in a reduction of the differences between the fasting and the post-feeding values. 5. These changes suggest a large involvement of endocrine cells in the adaptation of gut tissues, secretions and motility at birth, during the maintenance at the pre-ruminant stage and at weaning.
MeSH Terms
- Aging
- Animals
- Animals, Newborn
- Cattle
- Eating
- Gastrointestinal Hormones
- Peptides
- Weaning
Malnutrition is currently observed in aged people, and cholecystokinin is an important peripheral satiety signal. The aim of this study was to examine the effect of aging and protein-energy malnutrition on postprandial cholecystokinin (CCK) release. Non-randomized, cross-sectional comparison by age group. Gastroenterology section of a teaching hospital. Twenty-one human volunteers divided into three groups: young healthy subjects (Group 1: mean 29 years, n = 7), aged healthy subjects (Group 2, mean 80 years, n = 7), and aged subjects with an important degree of malnutrition (Group 3, mean 84.6 years, n = 7). Each subject ingested a standardized liquid meal after an overnight fast. Plasma cholecystokinin was measured using a sensitive bioassay before and after the ingestion of the liquid meal. Basal cholecystokinin levels were similar (0.9 to 1 pM equivalent CCK-8) in the three groups. Postprandial levels were significantly increased over basal (P less than 0.05). The maximal cholecystokinin value was lower in Group 1 (3.5 /- 0.8 pM equivalent CCK-8) and Group 2 (3.3 /- 0.77 pM equivalent CCK-8) than in Group 3 (8.3 /- 2 pM equivalent CCK-8) (P less than 0.05). Integrated plasma cholecystokinin was also similar in Group 1 (171 /- 38 pM.60 min), (P less than 0.05). The increase of postprandial maximal levels of cholecystokinin is more related to malnutrition than to aging.
MeSH Terms
- Adult
- Age Factors
- Aged
- Aged, 80 and over
- Aging
- Amylases
- Biological Assay
- Body Mass Index
- Cholecystokinin
- Cross-Sectional Studies
- Eating
- Energy Intake
- Humans
- Nutritional Status
- Prealbumin
- Protein-Energy Malnutrition
- Retinol-Binding Proteins
- Retinol-Binding Proteins, Plasma
- Satiety Response
- Serum Albumin
The effects of dopamine in vitro were investigated on the binding sites for cholecystokinin-8 (sulphated, CCK-8) and neurotensin in membrane preparations of the caudate-putamen and nucleus accumbens of post-mortem human brains. Dopamine reduced the IC50 value of competition curves with CCK-8 for [125I]CCK-8 binding in membranes from the caudate-putamen, but not the nucleus accumbens, with a maximal decrease of -25 /- 9% at 300 nM of dopamine. This decrease could be antagonized by 100 nM of SCH 23390 or 100 nM of raclopride. Kinetic analysis of [125I]CCK-8 binding showed a decrease in the first order dissociation rate constant and in the kinetic Kd (-22 /- 6% and -24 /- 6%, respectively) at 300 nM of dopamine, without any significant effect on the apparent or actual association rate constant. Competition curves with neurotensin versus [125I]neurotensin were not affected by dopamine (10-1000 nM) in membranes from the caudate-putamen or the nucleus accumbens. These results suggest that dopamine, by synergistic stimulation of both D1 and D2 receptors, selectively increases the affinity of CCK-8 receptors in the human caudate-putamen, by a selective inhibition of ligand dissociation. This increase may reflect a positive feed-back mechanism, further enhancing the modulatory effects of CCK-8 on dopamine neurotransmission.
MeSH Terms
- Adult
- Aged
- Aging
- Binding, Competitive
- Caudate Nucleus
- Dopamine Antagonists
- Female
- Humans
- In Vitro Techniques
- Kinetics
- Male
- Membranes
- Middle Aged
- Nucleus Accumbens
- Putamen
- Receptors, Cholecystokinin
- Receptors, Dopamine
- Receptors, Dopamine D1
- Receptors, Dopamine D2
- Receptors, Neurotensin
- Receptors, Neurotransmitter
1. Cholecystokinin and benzodiazepine receptor binding was evaluated in 2-, 9- and 18-month old rats in the brain regions where cholecystokinin octapeptide and gamma-aminobutyric acid are known to coexist in common nerve cells (frontal cortex, hippocampus). 2. There was a regionally selective alteration of hippocampal 3H-CCK-8 binding in the oldest age group, if compared to both young and adult animals. Non-linear regression analysis of binding data revealed significantly lower apparent number of binding sites (Bmax), and twofold (but not statistically significantly) higher binding affinity for the radiolabelled ligand. No differences between any age groups in 3H-flunitrazepam binding to benzodiazepine receptors were found. 3. The results suggest that changes in cholecystokinin receptor characteristics might contribute to the behavioural impairments in aged rats.
MeSH Terms
- Aging
- Animals
- Brain Chemistry
- Cerebral Cortex
- Flunitrazepam
- Hippocampus
- In Vitro Techniques
- Kinetics
- Male
- Rats
- Rats, Inbred Strains
- Receptors, Cholecystokinin
- Receptors, GABA-A
Under certain conditions, exogenously administered cholecystokinin (CCK) or its COOH-terminal octapeptide can terminate feeding and cause behavioral satiety in animals. Furthermore, high concentrations of CCK are normally found in the brains of vertebrate species. It has thus been hypothesized that brain CCK plays a role in the control of appetite. To explore this possibility, a COOH-terminal radioimmunoassay was used to measure concentrations of CCK in the cerebral cortex, hypothalamus, and brain stem of rats and mice after a variety of nutritional manipulations. CCK, mainly in the form of its COOH-terminal octapeptide, was found to appear in rat brain shortly before birth and to increase rapidly in cortex and brain stem throughout the first 5 wk of life. Severe early undernutrition had no effect on the normal pattern of CCK development in rat brain. Adult rats deprived of food for up to 72 h and rats made hyperphagic with highly palatable diets showed no alterations in brain CCK concentrations or distribution of molecular forms of CCK as determined by Sephadex gel filtration of brain extracts. Normal CCK concentrations were also found in the brains of four strains of genetically obese rodents and in the brains of six animals made hyperphagic and obese by surgical or chemical lesioning of the ventromedial hypothalamus. It is concluded that despite extreme variations in the nutritional status of rats and mice, CCK concentrations in major structures of the brain are maintained with remarkable constancy.
MeSH Terms
- Aging
- Animals
- Appetite Regulation
- Brain Stem
- Cerebral Cortex
- Cholecystokinin
- Feeding Behavior
- Female
- Food Deprivation
- Hypothalamus
- Mice
- Nutrition Disorders
- Nutritional Physiological Phenomena
- Obesity
- Rats
- Satiety Response