Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty exocrine pancreatic adenocarcinomas and 57 benign tumors induced in Syrian hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) were examined for the presence of argyrophil cells antiinsulin, -glucagon, -somatostatin, -pancreatic polypeptide (PP), -gastrin/CCK, -vasoactive intestinal polypeptide (VIP), and - neuron-specific enolase (NSE) reactive cells. Argyrophil - and antihormone-reactive cells were found in the normal pancreatic ducts and in the acini, as well as in hyperplastic and atypical ducts/ductules, tubular complexes, benign lesions, and in 80% of ductal adenocarcinomas. Insulin and antiNSE-reactive cells were the most common, followed in decreasing frequency by glucagon, somatostatin, and PP cells. Antigastrin-/CCK-and -VIP-reactive cells were found in two cases. Argyrophil cells were present in about 60% of the tumors with Grimelius staining and in 55% of those with Churukian-Schenk staining. Insulin cells were seen in ductal cancer that had grown into a lymph node and in the lymph node metastases of another cancer. A novel finding was the presence of argyrophil and insulin cells within the lumen of some malignant glandular structures. Coexistence of several peptide cells was found in 52% of the cancers. The presence of argyrophil and hormone-producing cells in induced pancreatic ductal/ductular lesions further strengthens the existence of a close developmental relationship between exocrine and endocrine cells of the pancreas.
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PMID:Immunohistochemical characterization of endocrine cells in experimental exocrine pancreatic cancer in the Syrian golden hamster. 135 11

Bilateral electrical lesioning of the hippocampal CA3 region (HCA3-EL) or anterior commissura hippocampi (ACHF-EL) caused marked elevations in plasma basal levels of insulin. 2 weeks later, fasting blood glucose levels were also augmented with decreased glucose tolerance. In contrast, the secretory response of pancreatic B cells to glucose stimulation was markedly enhanced. Following intravenous glucose tolerance test (IVGTT), the relative amounts of glucagon-like and insulin-like immunoreactants were reduced in the pancreatic islets of both HCA3-EL and ACHF-EL rats in comparison with the controls. In the HCA3-EL group, the relative amounts of somatostatin-like immunoreactants and gross numbers of such immunostained cells in islets were also decreased as compared with the control. No difference was seen in pancreatic-polypeptide-like immunoreactivities as assessed by immunohistochemistry plus microphotometry method. The above results suggest strongly that HCA3 and ACHF exert a tonic inhibitory action on the insulin secretion in the rat.
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PMID:[Effects of electrical lesioning of hippocampal CA3 region and anterior commissura hippocampi fornix on plasma insulin level and islet cells in the rat]. 136 Jul 7

A guanosine 5'-[gamma-[35S]thio]triphosphate-binding activity was detergent-extracted from Trypanosoma cruzi membranes. This binding activity was co-eluted from gel-filtration columns with a factor which, in a heterologous reconstitution system, blocks glucagon stimulation of adenylate cyclase activity in liver membranes. ADP-ribosylation of these membranes by pertussis toxin eliminated this blocking capacity. Incubation of T. cruzi membranes with activated pertussis toxin and [adenylate-32P]NAD+ led to the incorporation of radioactivity into a labelled product with an apparent M(r) of approx. 43,000. Crude membranes were electrophoresed on SDS/polyacrylamide gels and analysed, by Western blotting, with GA/1 anti-alpha common, AS/7 anti-alpha t, anti-alpha i1 and anti-alpha i2 polyclonal antibodies. These procedures led to the identification of a specific polypeptide band of about 43 kDa. Another polypeptide reacting with the SW/1 anti-beta antibody, of about 30 kDa, was also detected in the membrane fraction.
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PMID:Characterization of a Gi-protein from Trypanosoma cruzi epimastigote membranes. 144 3

Previous studies have demonstrated that glucagon-superfamily peptides stimulate insulin release from the pancreatic islets in a glucose dependent manner. In this study we have carried out a structure-activity study of their insulinotropic activity using a rat pancreas perfusion with 5.5 mM glucose concentration. The following peptides were examined: glucagon-like peptide-1(7-36)amide (tGLP-1), glucagon, gastric inhibitory peptide (GIP), peptide having an amino-terminal histidine and carboxy-terminal isoleucine amide (PHI), vasoactive intestinal polypeptide (VIP), growth hormone releasing factor(1-29)amide (GRF), GRF(1-27)amide and synthetic hybrid-peptides of PHI-GRF, PHI(1-11)-GRF(12-27) and PHI(1-20)-GRF(21-27). Their potencies were evaluated as: tGLP-1 = GIP > glucagon > PHI = VIP > PHI(1-20)-GRF(21-27) > PHI(1-11)-GRF(12-27) >> GRF(1-29) = GRF(1-27). It is clear that 0.1 nM tGLP-1 stimulated insulin release, whereas 1 microM GRF(1-29) did not. These results indicate that 1) in addition to N-terminal amino acid (histidine or tyrosine), position 4 (glycine), position 9 (aspartic acid) and position 11 (serine) in the amino acid sequence are important for their insulinotropic activity, 2) not only the N-terminal portion but also the C-terminal portion of these peptides contribute to their insulinotropic activity.
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PMID:Comparison of the insulinotropic activity of glucagon-superfamily peptides in rat pancreas perfusion. 146 9

Two autopsy cases with multiple hepatic metastases of pancreatic endocrine tumours and nodular regenerative hyperplasia of the liver (NRH) are reported. The tumour cells were positive for glucagon, insulin, gastrin and vasoactive intestinal polypeptide immunohistochemically and the serum gastrin was elevated in one case. In the other, tumour cells were positive for insulin. Controls failed to show NRH in the non-metastatic part of 35 autopsies of livers with multiple hepatic metastases. A combination of hepatotrophic hormonal factor(s) and disturbed hepatic circulation associated with hepatic metastases may be important in the development of NRH.
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PMID:Nodular regenerative hyperplasia of the liver associated with metastases of pancreatic endocrine tumour: report of two autopsy cases. 151 47

The goal of the present studies was to identify and characterize the site of secretin action in the liver. Sections of normal and bile duct-ligated rat livers were used for in vitro 125I-secretin receptor autoradiography. Saturable binding was observed in both normal and bile duct-ligated livers but was much greater in the bile duct-ligated preparations. Binding was limited to biliary epithelium and the increased secretin binding observed in the ligated livers correlated with the increase in ductular tissue. Saturable binding was inhibited in a dose-dependent fashion by increasing concentrations of nonradioactive secretin. Analysis of saturation binding showed that 125I-secretin binding was best fit by a one-site receptor model with a Kd of 5.3 +/- 1.1 nmol/L. Glucagon, vasoactive intestinal polypeptide, gastric inhibitory polypeptide, growth hormone-releasing hormone, and cholecystokinin did not inhibit saturable 125I-secretin binding at concentrations of 1 pmol/L to 1 mumol/L. The authors conclude that high-affinity, specific secretin binding sites are present in rat intrahepatic biliary epithelium. When bile ducts are stimulated to proliferate by bile duct ligation, secretin binding is also increased.
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PMID:Localization and characterization of secretin binding sites expressed by rat bile duct epithelium. 153 32

The plasma concentrations of seven gut regulatory peptides were measured in 11 infants suffering from acute gastroenteritis. Samples were taken at the time of the acute illness, upon reintroduction of feeding, and three months after recovery. These results were compared with controls. In the infants with diarrhoea, a massive increase in the fasting plasma mean (SEM) concentrations of enteroglucagon was found at the time of illness (1292 (312) v 79 (27) pmol/l), with concentrations of pancreatic glucagon, peptide tyrosine tyrosine, and motilin also being increased (17.8 (3.1) v 6.3 (1.1) pmol/l, 114.6 (15.2) v 37.0 (11.0) pmol/l, 217.6 (44.1) v 98.5 (18.3 pmol/l) respectively). The preprandial concentrations of motilin were found to be still increased at recovery (183.9 (35.4) pmol/l), but the concentrations of the other three peptides had returned to normal values. No differences in plasma concentrations of vasoactive intestinal polypeptide, neurotensin, or pancreatic polypeptide were found. An increased intestinal permeability was demonstrated at the time of diarrhoea by the urinary ratio of lactulose to mannitol, suggesting simultaneous gut damage. The effects of regulatory peptides may be relevant to the pathophysiology of gastroenteritis in infants.
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PMID:Gut regulatory peptides and intestinal permeability in acute infantile gastroenteritis. 157 47

After ingestion of glucose both GIP (gastric inhibitory polypeptide, glucose-dependent insulinotropic polypeptide) and GLP-1(7-36amide) (glucagon-like polypeptide-1, 7-36amide) may play a physiological role in augmenting insulin release. Their insulinotropic effect was compared in isolated rat islets after 24-h maintenance in tissue culture (11 mmol l-1 glucose). Ten islets per vial were then incubated in Krebs-Ringer-Hepes buffer for 30 min; insulin was measured radioimmunologically. Both hormones were always compared in the same experiment. At 16.7 mmol l-1 glucose both GIP and GLP-1(7-36amide) 2 x 10(-10) mol l-1 significantly increased insulin release; 10(-10) mol l-1 of either hormone had no significant effect. The response at 10(-9) and 10(-8) mol l-1 was similar for both; at 4 x 10(-10) mol l-1 GLP-1(7-36amide), however, was clearly more effective than GIP. At low glucose (2.8 or 5.0 mol l-1) no significant differences were found. A concentration of 10(-8) mol l-1 of both hormones was slightly stimulatory. At 8.3 mmol l-1 glucose, 10(-9) mol l-1 GLP-1(7-36amide) was 60% more effective than GIP (4.8 +/- 0.4 vs. 3.0 +/- 0.4, n = 13, P less than 0.005), the response to 10(-8) mol l-1 was similar. These data show comparable effects of high concentrations of GIP and GLP-1(7-36amide) on glucose-induced insulin release; at presumably physiological concentrations, however, GLP-1(7-36amide) was clearly more effective. The combination of the two peptides was not more than additive, suggesting that they act via the same final mechanism.
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PMID:Comparison of the effect of GIP and GLP-1 (7-36amide) on insulin release from rat pancreatic islets. 158 39

1. Localization and pharmacological properties of the vasoactive intestinal polypeptide (VIP) receptors in rat circle of Willis arteries and in the arteries of pial-arachnoid membrane were studied using light microscope autoradiography combined with radioreceptor binding techniques. 2. [125I]-VIP was specifically bound to sections of rat cerebral arteries with a dissociation constant value of 0.5 nM and a binding site density of 80 fmol mg protein-1. Radioreceptor binding experiments revealed that the binding characteristics of [125I]-VIP were consistent with the labelling of specific VIP receptors. The rank order of potency of various substances tested to inhibit [125I]-VIP binding was the following: VIP greater than peptide histidine methionine greater than secretin greater than glucagon. 3. Light microscope autoradiography revealed the localization of [125I]-VIP binding sites in the medial layer of circle of Willis and pial arteries. Quantitative determination of [125I]-VIP binding site density in the different circle of Willis arteries demonstrated a higher accumulation of silver grains in the anterior than in the posterior cerebral arteries. Pial arteries are richer in VIP receptor sites than circle of Willis arteries. 4. These results suggest that the physiological neurogenic vasodilation elicited by VIP on cerebral arteries is mediated by the interaction with specific receptor sites located primarily within cerebral vessels structures involved in the control of cerebrovascular resistances.
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PMID:Vasoactive intestinal polypeptide receptors in rat cerebral vessels: an autoradiographic study. 166 Aug 95

Pituitary adenylate-cyclase-activating polypeptide (PACAP), a novel brain-gut hormone, was isolated from ovine hypothalami and represents the latest mammalian member of the secretin-glucagon peptide family. PACAP exists in two C-terminally amidated molecular forms, PACAP(1-27) and PACAP(1-38), comprising 27 or 38 amino acid residues, respectively. In order to identify a specific receptor for PACAP, we studied binding of 125I-labelled PACAP(1-27) to plasma membranes from rat brain. We identified a single high-affinity binding site (Kd, 340 pM and Bmax, 3.34 pmol/mg), specific for synthetic PACAP(1-38) and PACAP(1-27). Hormone binding was reversible and time, protein and temperature dependent. In contrast, neither the analogues PACAP(1-23), PACAP(18-38) and PACAP(3-25), nor vasoactive intestinal peptide (VIP), secretin and growth-hormone-releasing factor (GRF) revealed significant binding at concentrations up to 1 microM. A specific receptor protein, with an apparent molecular mass of 60 kDa, was identified by means of affinity cross-linking with disuccinimidyl suberate (DSS) and ethylene glycol disuccinimidyl suberate (EGS). PACAP receptors are associated with a GTP-binding protein as determined by the influence of different nucleotides on PACAP binding. PACAP-binding activity was solubilized with the detergents 3-[(3-cholamidopropyl)dimethylammonio]2-hydroxy-1-propane sulfonate (Chapso) or Triton X-100 and was characterized as a high-molecular-mass receptor complex (400 kDa) by non-reducing size-exclusion chromatography on Sepharose CL-6B. These data imply the following: high-affinity PACAP receptors are expressed abundantly on rat-brain plasma membranes; PACAP receptors are specific for PACAP and show no affinity for VIP, secretin and GRF; the PACAP receptor molecule has an apparent molecular mass of 60 kDa; the PACAP receptor complex is associated with a GTP-binding protein.
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PMID:Characterization of a guanosine-nucleotide-binding-protein-coupled receptor for pituitary adenylate-cyclase-activating polypeptide on plasma membranes from rat brain. 166 20


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