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)

The effects of intraperitoneal injections of pancreatic glucagon and bombesin on meal size were tested in female rats in the dynamic phase of ventromedial hypothalamic (VMH) hyperphagia. Both pancreatic glucagon (100-2500 micrograms/kg) and bombesin (4-16 micrograms/kg) inhibited meal size in a dose-related manner. Percent inhibitions of meal size in VMH-lesioned and control rats did not differ significantly. These results suggest that the VMH is not necessary for peripheral administration of either pancreatic glucagon or bombesin to elicit postprandial satiety.
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PMID:Pancreatic glucagon and bombesin inhibit meal size in ventromedial hypothalamus-lesioned rats. 353 24

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

The capacity of autotransplanted (ATP) distal pancreas segments with systemic venous and peritoneal exocrine drainage to support physiologic control of plasma glucose levels was tested, and compared with the functions of "simulated autotransplants" (SATP) prepared with similar dissection and peritoneal exocrine drainage, but with hepatic portal venous drainage, in dogs. In ATP in the postabsorptive state, plasma levels of glucose, immunoreactive insulin (IRI) and immunoreactive glucagon (IRG1) were normal. Autotransplants resulted in impaired glucose tolerance after meals with impaired early insulin responses, and the normal brisk rise of IRG1 in the plasma was delayed and reduced through the first 30 min of feeding. In ATP, also, the response to bombesin was abnormal; the normal stimulation of release of both IRI and IRG1 was delayed in both cases. In studies of responses to oral and intravenous glucose in ATP and SATP dogs, similar mild degrees of glucose intolerance were found with both routes of administration; however, whereas in ATP dogs increases of IRI were highly exaggerated with both routes of administration of glucose, in SATP dogs plasma IRI rose from subnormal levels in the postabsorptive state through subnormal increments with both routes of administration. Further studies are necessary to determine the relative importance of denervation and reduction of the mass of the pancreas in these effects, and to assess the significance of the differences in blood insulin levels in the two preparations.
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PMID:Pancreatic endocrine responses to nutrients and bombesin after segmental pancreas autotransplantation in dogs. 355 27

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

Twelve endocrine cell types immunoreactive for either 5-hydroxytryptamine (5-HT), somatostatin, gastrin, motilin, neurotensin, bovine pancreatic polypeptide (BPP), avian pancreatic polypeptide (APP), pancreatic glucagon, enteroglucagon, glicentin, secretin or cholecystokinin (CCK) were found in gastrointestinal mucosa of Caiman latirostris. Moderate numbers of enteroglucagon-immunoreactive cells, a few 5-HT-, somatostatin- and motilin-immunoreactive cells and rare pancreatic glucagon-immunoreactive cells were found in the fundic stomach. Numerous gastrin-immunoreactive cells and moderate numbers of somatostatin- and motilin-immunoreactive cells were seen in the pyloric stomach. Moderate numbers of 5-HT-, gastrin-, motilin- and enteroglucagon-immunoreactive cells, a few somatostatin-, neurotensin- and BPP-immunoreactive cells, and rare APP-, pancreatic glucagon-, glicentin-, secretin- and CCK-immunoreactive cells were observed in the proximal intestine. Moderate numbers of 5-HT-immunoreactive cells, small to moderate numbers of neurotensin- and enteroglucagon-immunoreactive cells and occasional somatostatin-, motilin- and BPP-immunoreactive cells were seen in the distal intestine. Moderate numbers of neurotensin-immunoreactive cells and a few 5-HT-immunoreactive cells were found also in the cloaca. Cells immunoreactive for gastrin releasing polypeptide, bombesin and gastric inhibitory peptide were not observed in the caiman gastrointestinal epithelium. The differences in endocrine cell types between the caiman and alligator are discussed in terms of their topographic distribution.
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PMID:An immunohistochemical study of the endocrine cells in the gastrointestinal mucosa of the Caiman latirostris. 366 53

Pancreatic glucagon (PG) elicits satiety in normally feeding rats but fails to inhibit sham feeding in rats with open gastric cannulas. This suggests that a gastric or postgastric food stimulus is necessary for PG's satiating action. To determine whether bombesin or cholecystokinin might provide such a stimulus, sham-feeding rats received simultaneous intraperitoneal injections of 100-800 micrograms/kg of PG and doses of bombesin or cholecystokinin (CCK) that were near the threshold for inhibition of sham feeding. PG and 0.15-to 0.30-micrograms/kg CCK combinations inhibited sham feeding potently (37.6 +/- 7.0 and 62.0 +/- 9.4%, respectively). In contrast, PG and 0.25- to 0.50-microgram/kg bombesin combinations did not significantly affect sham feeding. Behavioral observations indicated that the inhibition of sham feeding by PG plus CCK did not disrupt the normal postprandial satiety sequence of behavior, PG, 400 micrograms/kg, plus 0.15 micrograms/kg of CCK did not inhibit sham drinking in 18-h water-deprived rats. PG, 400 micrograms/kg, plus 0.30 microgram/kg of CCK did inhibit sham drinking, although the effect (34.6 +/- 6.6%) was significantly less than the effect on sham feeding (75.5 +/- 9.7%) in the same rats. These data indicate that CCK is a sufficient food stimulus to permit PG to inhibit sham feeding. Furthermore, this inhibitory effect appears to result from a functional synergism of PG and CCK.
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PMID:Pancreatic glucagon and cholecystokinin synergistically inhibit sham feeding in rats. 368 74

Pancreatic glucagon (PG), cholecystokinin (CCK), and bombesin (BBS) were injected individually and in combination before nondeprived rats were offered condensed milk test meals. Peptide doses that were individually below the threshold for reliable inhibition of meal size (0.15 microgram/kg CCK, 0.75 microgram/kg BBS, 100 micrograms/kg PG) combined to inhibit meal size 19-40%. The inhibitions produced by combinations including CCK were 16-21% more than the sum of the inhibitions elicited by individual injections. This indicates a potentiation of inhibition. In contrast, when peptide doses were increased, the inhibitory effects of the combinations were similar to the sum of the individual injections. None of the peptide treatments disrupted the normal behavioral sequence of postprandial satiety, and they did not reliably affect water intake in water-deprived rats. We conclude that exogenous CCK, BBS, and PG can interact to potentiate postprandial satiety.
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PMID:Combined injection potentiates the satiety effects of pancreatic glucagon, cholecystokinin, and bombesin. 380 25

A major physiological role of calcitonin in humans appears to be regulation of skeletal turnover. It has been suggested that another function of calcitonin is to prevent post-prandial rises in calcium, particularly in animals, but the importance of such a function in man remains to be determined. Although it is known that calcitonin has an inhibitory effect on the secretion of gastrin and insulin, its actions on other gut and pancreatic hormones have not previously been studied. To investigate interrelations between calcitonin and gastrointestinal regulatory peptides, 0.5 mg synthetic human calcitonin was administered to 10 fasting patients. No changes in the plasma concentrations of glucose, somatostatin, neurotensin, enteroglucagon, vasoactive intestinal polypeptide or bombesin were observed. In contrast, profound falls in the circulating levels of gastrin, insulin and pancreatic glucagon were seen, reaching a maximum shortly after the peak of plasma calcitonin concentration. Marked changes were also observed in the levels of motilin, pancreatic polypeptide and, to a lesser extent, gastric inhibitory polypeptide, but the maximal falls occurred about 40 min later, coinciding with a significant fall in serum calcium. It is possible that the effect of calcitonin on these hormones was direct, perhaps receptor-mediated. The falls in levels of motilin and pancreatic polypeptide could have been further enhanced by changes in extracellular calcium ion concentrations. Whether any of these effects of calcitonin occur physiologically remains to be determined. However, these findings suggest new therapeutic possibilities for calcitonin.
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PMID:Effect of calcitonin on gastrointestinal regulatory peptides in man. 389 80

Pancreatic endocrine cells were stained immunocytochemically for insulin, glucagon, somatostatin and pancreatic polypeptide by the PAP technique or sequentially for two hormones by the PAP followed by an indirect immunogold procedure. Pancreatic endocrine cells of Chrysemys are found scattered as single cells or small aggregates throughout the exocrine parenchyma; only the splenic region shows islets consisting of a B cell core surrounded by a loose mantle of A cells and occasional D cells. PP cells were not found in this splenic portion but were found scattered throughout the remainder of the pancreas. In contrast to the typical vertebrate islet, Chrysemys pancreatic endocrine cells are characterized by a lack of preferential association of one cell type with another and suggests that paracrine regulatory mechanisms may not be operable in this species. Insulin secretion from pieces of Chrysemys pancreas has been measured in incubation and perifusion systems employing a heterologous radioimmunoassay. Insulin release by Chrysemys B cells is enhanced by elevated levels of glucose (300 mg/dl), however, response appears to be somewhat slower compared to other vertebrate B cells. Gastrin, secretin, neurotensin, motilin, serotonin, PYY, glucagon, gastric inhibitory polypeptide, somatostatin and insulin were demonstrated immunocytochemically in open-type GEP cells of the mucosal epithelium of the Chrysemys intestine. Of these cells, gastrin, neurotensin and insulin cells appear to be the most numerous while the other types appear less frequently. Cells containing PP, bombesin, cholecystokinin and substance P could not be demonstrated. The localization of insulin to GEP cells of the turtle intestine is an unusual finding but has been confirmed by radioimmunoassay of extracts of the intestinal mucosa.
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PMID:The gastro-entero-pancreatic system of the turtle, Chrysemys picta. 391 12


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