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)

Functional and specific receptors for vasoactive intestinal peptide (VIP) (determined by their capacity to bind 125I-VIP and activate adenylate cyclase) and cyclic AMP-dependent phosphodiesterase activities were characterized in enterocytes of human fetal small intestine between 18 and 23 weeks of gestation. Half-maximal stimulation of the cyclase and inhibition of 125I-VIP binding in membrane preparations were respectively observed at 1.4 and 5 X 10(-10) M VIP. The peptides structurally related to VIP activated the cyclic AMP generating system at pharmacological doses (10(-7) M and above) in the following order of potency: VIP greater than PHI greater than GRF greater than secretin. Other peptides or test substances, including GIP, pancreatic glucagon, somatostatin-14, gastrin, CCK, neurotensin, pancreatic polypeptide, PYY, substance P, histamine and isoproterenol are inactive in this system, while the ubiquitous adenylate cyclase activators NaF, forskolin and prostaglandins were effective. These results, combined with the appearance of intestinal VIP in nerve fibers at 8 weeks and with the morphological and enzymatic maturation at 9-12 weeks of the intestinal mucosa, indicate that this neuropeptide may regulate either the differentiation or function of enterocytes during the early development of human intestinal mucosa.
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PMID:Vasoactive intestinal peptide receptor activity in human fetal enterocytes. 298 18

The sphincter of Oddi is the smooth muscle connection between the bile duct and the duodenum. Its physiological function is associated with a regular motility characterized by phasic contractions superimposed on the sphincter of Oddi baseline pressure. Recently introduced ERCP-manometry permits further studies of sphincter of Oddi pharmacology. A number of drugs have so far been studied. Sedatives of the diazepam type had no effect on the sphincter, while butylscopolaminium bromide, a typical neurotropic agent, brings about cessation of the sphincter motility for 3-8 minutes. Hymecromon lowered the sphincter baseline pressure from 9.8 to 7.8 mmHg. A 1.2 mg sublingual dose of nitroglycerin, a typical musculotropic agent, caused significant relaxation of the sphincter, and decreased baseline pressure from 8.9 mmHg to 2.9 mmHg; Sphincter motility was not affected. Morphine-like analgetics, in particular pentazocine, elevated sphincter baseline pressure, but buprenorphine and tramadol did not. Pharmacological doses of gastrointestinal hormones also affect the sphincter; CCK octapeptide, glucagon and secretin are able to decrease sphincter of Oddi baseline pressure, and CCK octapeptide abolishes sphincter motility. Sphincter of Oddi pharmacology is of clinical interest. The administration of sphincter-relaxing agents, in particular nitroglycerin and butylscopolaminium bromide, enables the endoscopist to extract small common bile duct stones without previous papillotomy. Analgetics that induce sphincter contraction and thus hinder the flow of bile and pancreatic juice, may be helpful for the treatment of pain in patients with pancreatico-biliary disease. Investigations into the effect of CCK on the healthy and diseased sphincter permit us to identify patients with sphincter dysfunction using a special CCK-provocation test.
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PMID:Pharmacology of the sphincter of Oddi. 304 55

Chromogranins A and B and secretogranin II have been localized in a wide spectrum of gastroenteropancreatic endocrine/paracrine cells. Chromogranin A immunoreactivity showed the widest distribution and was displayed by glucagon-, PP-, gastrin-, gastrin-CCK-, secretin-immunoreactive cells, the most intense stainings being peculiar of enterochromaffin cells. Chromogranin B immunoreactivity was detected in gastrin- and glucagon cells and in some enterochromaffin cells containing also chromogranin A. Secretogranin II was paired to chromogranin A in glucagon cells of pancreatic islets or occurred alone in glycentin/PP cells of colonic mucosa. Neither of the chromogranins nor secretogranin II have been so far detected in somatostatin-, GIP-, or motilin-immunoreactive cells. Chromogranin A but not chromogranin B or secretogranin II has been detected in the gastric argyrophilic ECL cells.
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PMID:Chromogranins A and B and secretogranin II in hormonally identified endocrine cells of the gut and the pancreas. 322 65

In the studies reported here we demonstrate that bombesin decreases food intake in wolf (Canis lupus) pups without altering glucose or insulin levels. A high dose of cholecystokinin-octapeptide (CCK, 5 micrograms/kg) decreased food intake. CCK produced a transient increase in insulin, without altering glucose. Glucagon (0.5 mg/kg) failed to decrease food intake despite producing a marked hyperglycemia and hyperinsulinemia. Calcitonin was ineffective at decreasing food intake, although it did decrease the time spent feeding. These studies suggest a potential role for peripheral peptides in food regulation in the wolf.
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PMID:The effect of peripheral administration of peptides on food intake, glucose and insulin in wolf pups. 355 Jul 28

Siberian hamsters (Phodopus sungorous sungorous) decrease their food intake when exposed to short ("winter-like") photoperiods. The cause of this naturally-occurring hypophagia is unknown, but it may be due to a heightened sensitivity to the factors that normally terminate food intake in long photoperiods, such as the putative satiety peptides. The purpose of the present investigation was to test whether there would be an enhanced sensitivity to the inhibitory effects of some of these peptides on food intake in short relative to long days. Ad lib-fed, adult female Siberian hamsters were housed in a long photoperiod (LD 14:10) and injected with bombesin, glucagon, cholecystokinin octapeptide (CCK-8) and calcitonin (CT). Food intake was monitored 1, 2, 4, 6, and 24 hr post-injection. Bombesin and glucagon had no effect on food intake in long day-housed hamsters. CCK-8 and CT inhibited food intake; however, CCK-8 did so without any apparent behavioral disruption, while CT produced a marked and prolonged depression of behavior. After 10 weeks of exposure to a short photoperiod (LD 8:16) the hamsters were tested again. The previously ineffective dose of bombesin greatly inhibited food intake following short photoperiod exposure. In addition, an increased inhibition of food intake by CCK-8 was also found. In contrast, glucagon did not decrease food intake and CT still produced its non-specific, behaviorally disruptive effects. To our knowledge, this is the first demonstration that the effectiveness of a putative satiety peptide can be dependent upon a change in the photoperiod.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Photoperiod-peptide interactions in the energy intake of Siberian hamsters. 356 18

In cultured rat hepatocytes, the effects of gut hormones on bile acid uptake and release were studied. It was found that cultured hepatocytes continued to secrete bile acids into the culture medium and incorporated them effectively as a function of incubation time. Gut hormones such as secretin, glucagon, vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI), gastric inhibitory polypeptide (GIP), tetragastrin, cholecystokinin-octapeptide (CCK-8), pancreatic polypeptide (PP), neurotensin substance P, beta-endorphin (beta-End), methionine-enkephalin (Met-enk), motilin, bombesin and somatostatin (SS) had no effect on bile acid uptake by cultured hepatocytes. In bile acid release studies, only secretin caused a dose-dependent stimulation of bile acid release, while other gut hormones had no effect on bile acid release into medium. These results indicate that secretin acts directly on cultured rat hepatocytes and/or bile canaliculi, besides its effect on the bile duct, and influences bile acid metabolism.
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PMID:Effects of gut hormones on bile acid uptake and release in cultured rat hepatocytes. 359 53

The small intestine of Vipera aspis, Natrix natrix and Natrix maura has been investigated for the presence of six gastrointestinal peptides reported to occur in Mammals. Gastrin/CCK and somatostatin were present in endocrine cells of the gut of all the species investigated. The neuropeptide vasoactive intestinal polypeptide was located within nerve terminals and in body cells only in the small intestine of Vipers and was absent in the Natricinae investigated. No immunoreactivity was found with the antisera to glucagon, secretin and motilin.
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PMID:Immunohistochemical localization of gut peptides in the small intestine of snakes. 379 35

Cholecystokinin-8 (CCK-8) was injected into the lateral cerebral ventricles (LV) of conscious sheep to determine its effect on secretion of three hormones important in regulation of peripheral metabolism: growth hormone (GH), glucagon, and insulin. Three hr continuous LV injection of 0.64 pmol/min CCK-8 decreased plasma insulin concentration approximately 30% throughout the three hr period, compared to control injection, and this effect occurred independently of whether or not the sheep were permitted to eat during injection. Only high doses of desulfated CCK-8 affected plasma insulin levels, thus suggesting the involvement of specific CCK receptors. Plasma glucose and GH concentrations were unaffected by LV injections, but plasma glucagon concentration was also decreased by CCK-8. LV injection of 0.64 pmol/min CCK-8 in sheep given an IV bolus injection of glucose (1.0 g/kg body mass) resulted in significantly lower plasma insulin and higher plasma glucose concentrations than during control LV injections; thus CCK-8 is capable of suppressing insulin secretion even under stimulated conditions. Since cisterna magna injections of CCK-8 were not effective in suppressing insulin secretion, more rostral brain sites are probably responsible for mediating this effect.
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PMID:CCK-octapeptide injected into cerebral ventricles of sheep decreases plasma insulin level. 388 48

In order to investigate the effect of gastrointestinal hormones upon the secretion of extrapancreatic glucagon, tetragastrin, secretin, caerulein and cholecytokinin-pancreozymin octapeptide (CCK-octa) were administered during saline or arginine infusion in pancreatectomized dogs. Intravenous administration of tetragastrin (7 micrograms/kg) did not elicit any changes in plasma glucagon during saline infusion, while the plasma glucagon increased significantly following tetragastrin infusion during arginine infusion. The administration of secretin (3 U/kg) did not affect the plasma level of glucagon during saline or arginine infusion at all. Plasma glucagon did not change after the administration of caerulein (0.5 microgram/kg) during saline infusion, whereas it increased significantly following caerulein administration during arginine infusion. Intravenous administration of CCK-octa in a dose of 20 U/kg did not affect the plasma level of glucagon during saline infusion but exerted a significant rise of extrapancreatic glucagon during arginine infusion. It is concluded from the present experiment that the administration of tetragastrin, caerulein or CCK-octa enhances the release of extrapancreatic glucagon stimulated by arginine infusion while secretin infusion does not affect the secretion of extrapancreatic glucagon.
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PMID:Response of extrapancreatic glucagon to gastrointestinal hormones in pancreatectomized dogs. 390 14

Water and electrolyte flux in response to systemic administration of four different gastrointestinal hormones were studied in a human with a chronic Thiry-Vella ileal loop. Gastrin infusion with a pharmacological dose of 4 micrograms/kg-hr has no effect. Responses to glucagon were proportional to infused doses with directly increased absorption of water and electrolytes (except bicarbonate). However, when gastrin was infused simultaneously with glucagon, the enhanced absorption was inhibited. Secretin only transiently increased absorption of fluid and electrolytes. In contrast to its effects on jejunum, CCK increased both water and electrolyte absorption from the ileum.
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PMID:Water and electrolyte absorption from a human Thiry-Vella ileal loop. Responses to systemic administration of gastrin, glucagon, secretin, and cholecystokinin. 396 99


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