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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prenatal development of rat pancreatic endocrine cells was investigated by the immunoperoxidase technique and the following results were obtained: 1) Glucagon immunoreactive cells are first endocrine element of the pancreas appearing already on day 11 of gestation, when the dorsal pancreatic bud is still quite small and the ventral pancreatic primordium is hardly swollen out. Most of the glucagon reactive cells are located in the epithelium of the foregut and the dorsal pancreatic bud but a few of them are attached to the base of the epithelium from the outside. 2) Insulin and pancreatic polypeptide (PP) immunoreactive cells are first demonstrable in small cell clusters budding from the exocrine tubules on day 14, whereas somatostatin and gastrin reactive cells on day 17 and 18, respectively. These findings support the hypothesis that the majority of pancreatic endocrine cells is derived from the epithelium of the foregut. 3) PP reactive cells, appearing first on day 14, assume gradually a peripheral position in the growing islet of Langerhans. Immediately before birth they attain the population and flattened cell shape comparable to those in adult pancreas. Their counterpart in the duodenum is found as open type basal-granulated cells in the rat fetus. 4) Noteworthily, glucagon-like immunoreactivity is found in some neuron-like cells of the Auerbach's plexus between the muscle layers of the duodenum on day 19.
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PMID:Development of pancreatic endocrine cells in the rat fetus. 39 8

A case of carcinoma of the stomach associated with severe hypoglycemia is reported. Diagnosis of insulinoma was excluded on the basis of history as well as laboratory tests. Postmortem examination revealed widespread small metastases to various organs; no metastasis was found in the pancreas; the histology of this gland did not show any pathological finding. No impairment in pituitary, thyroid, adrenal and liver function was detected. Fasting blood sugar ranged from 18 to 56 mg/100 ml. An oral glucose tolerance test showed a diabetic pattern with low insulin. Tolbutamide, glucagon and glucose injected i.v. gave only a moderate rise in plasma insulin levels; plasma glucagon response to arginine was subnormal. The determination of NSILA-s and gastrin in the serum of this patient gave normal values. Diazoxide infusion induced an increase in blood glucose and subsequent treatment with diazoxide relieved hypoglycemia for some months. The occasional detection of an islet cell antibody by immunofluorescence in this case is not easily understandable, but it might partly account for the carbohydrate intolerance. An impairment in gluconeogenesis dependent upon some substrate deficiency might account for the hypoglycemia in this patient.
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PMID:Gastric carcinoma associated with severe hypoglycemia sensitive to diazoxide. 39 98

The direct effect of insulin on the secretion of insulin (as measured by C-peptide), glucagon, gastric inhibitory polypeptide, and gastrin was studied in normal subjects by infusing insulin while the plasma level of glucose was maintained in the normal fasting range (euglycemic clamp). Insulin-induced hypoglycemia resulted in increases in circulating glucagon and gastric inhibitory polypeptide, a decrease in C-peptide, and no change in gastrin levels. In contrast, during the euglycemic clamp, insulin was found to behave a direct suppressive effect on the secretion of glucagon, C-peptide, and gastrin, but no effect on levels of gastric inhibitory polypeptide.
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PMID:Direct effect of insulin on secretion of insulin, glucagon, gastric inhibitory polypeptide, and gastrin during maintenance of normoglycemia. 40 Jul 22

The gastrointestinal contribution to carbohydrate metabolism includes carbohydrate absorption and the release of gastrointestinal hormones that interact with the endocrine pancreas. To learn the contributions to the enteroinsular axis from different levels of the gastrointestinal tract and different nutrients in chyme, we determined serum concentrations of glucose, gastric inhibitory peptide (GIP), insulin, and glucagon postprandially in six normal subjects who underwent diversion of chyme just proximal to an occlusive balloon at the ligament of Treitz and jejunal infusion of saline or chyme carbohydrate, protein, and lipid, separately or in combination. Postprandial elevations of serum glucose, GIP, and insulin and decrease of serum glucagon were elicited predominantly from the bowel and its contents distal to the ligament of Treitz. In this segment, each chyme nutrient (but especially carbohydrate) significantly stimulated factors affecting carbohydrate metabolism. Protein and lipid were able to block carbohydrate-induced glucagon inhibition. The gastroduodenal segment, although containing several proposed insulinotropic hormones (gastrin, secretin, and cholecystokinin), had no effect on serum glucose of glucagon and stimulated only small insulin and GIP responses.
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PMID:Intestinal nutrient influence on the enteroinsular axis. 40 Jul 36

1) In electively immuno-induced carcinomas of the exocrine pancrease in Mice, where A (glucagon) and B (insulin) endocrine cells persist, cells with a pancreatic polypeptide immunoreactivity are also detected, even in late evolution stages. These cells, like D cells, containing somatostatin, are localized only in the pancreatic remains surrounding the anaplasic carcinomatous tissue: islets, adenomatous parenchyma, and ductular epithelium. Ultrastructure of these cells shows their active elaboration of numerous chracteristic secretion granules. (2) Immunocytoenzymatic detection of gastrin is negative in the exocrine and endocrine pancreatic tissues. However one of the anti-gastrin sera used gives a positive reaction, in some carinomatous cells only. Does this immunoreactivity characterize a polypeptide specific to the pancreatic carcinomatous cell?
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PMID:[Presence of "pancreatic polypeptide" cells, and gastrin immunoreactivity in immuno-induced exocrine pancreas carcinoma]. 41 May 28

Little is known on the enteral stimuli for gastro-intestinal hormone release in newborn infants. We have compared the effect of the first feed of human breast milk (5 ml/kg) or 10% dextrose (5 ml/kg) on blood glucose and plasma gastrin, enteroglucagon, Gastric Inhibitory polypeptide (GIP), pancreatic glucagon, and insulin in 21 full-term infants at 4--6 hours of age. The first feed of human milk caused a rise in blood glucose and plasma insulin, gastrin and enteroglucagon, but no change occurred in GIP or pancreatic glucagon. The 10% dextrose feed did not stimulate enteroglucagon release, although similar changes occurred in blood glucose and plasma insulin and gastrin. We conclude that the composition of the feed influences the pattern of gastro-intestinal hormone release during the first hours of life and that the entero-insular responses to feeding differ in the neonate and the adult.
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PMID:The effect of feeds of differing composition on entero-insular hormone secretion in the first hours of life in human neonates. 41 93

The responses of plasma gastro-entero-pancreatic (GEP) hormones and free fatty acids (FFA) to a standard mixed meal before and after starvation have been measured. Raised insulin, glucose and FFA levels were found following refeeding after starvation and levels of secretin and C-terminal glucagon-like-immunoreactivity (C-GLI), raised by starvation, were rapidly suppressed on refeeding. The responses of gastrin and N-terminal glucagon-like-immunoreactivity (N-GLI) to a standard mixed meal were not altered by starvation. Although this study does not directly support that secretin and glucagon are responsible for the hyperglycaemia or hyperinsulinaemia of starvation diabetes, a role for both hormones in the raised FFA levels is proposed, as well as a role for glucagon in the initial hyperglycaemic response to a meal after starvation.
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PMID:The gastro-entero-pancreatic hormone secretion after a mixed meal in normal subjects before and after a 72 hour period of starvation. 44 30

The peptides usually called gastrointestinal hormones belong to a broader group of regulatory substances distributed in many parts of the body and delivered to their targets not only by the blood but also by neural and paracrine paths. The neural, endocrine, and paracrine cells as a group might be called "regulator cells" and the chemical messengers they produce might be called "regulins." Twenty peptides have been isolated from the alimentary tract and pancreas: 12 have been sequenced, 4 have been partially sequenced, and 4 more have been identified only by immunoreactivity. Gastrin, gastric inhibitory peptide, glucagon, insulin, and secretin can be regarded as established hormones that are released into the blood by identified stimuli and produce identified physiological responses. The evidence for the hormonal status of cholecystokinin, pancreatic polypeptide, and motilin is incomplete but suggestive. The possible physiological roles of the other 12 peptides remain to be determined. If specific antagonists of these peptides can be found, they will greatly assist in elucidating the peptides' physiological roles.
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PMID:Chemical messengers: a view from the gut. 45 21

Strong secretin-like immunofluorescence has been demonstrated in endocrine-like cells from the gastric epithelium of Styela. These cells also stain with lead haematoxylin and exhibit a brilliant formaldehyde-induced fluorescence, but do not show any other cytochemical features characteristics of the mammalian APUD series. Tests with antisera to glucagon, gastrin and somatostatin all proved negative. In the oesophagus tests with all four antisera proved negative. The significance of these results is discussed in relation to the phylogeny of vertebrate gastro-intestinal hormones.
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PMID:A cytochemical and immunofluorescence study of endocrine cells in the gut of the ascidian Styela clava. 46 92

The influence of restraint stress on serum calcium (Ca) and phosphate was studied in normal and thyroidectomized rats. In addition the response of gastric stress ulcer index, blood gastrin and glucagon to exogenous Ca was investigated. In intact as well as in thyroidectomized animals serum total, ionised and previously injected radioactive Ca decrease during an 8h stress period, whereas inorganic phosphate increases. Together with a constant specific activity these findings are consistent with hypoparathyroidism and calcitonin independent hypocalcemia during stress. Intragastric infusion of 45 mg/kg Ca-gluconate per 8h proves to be a potent anti-stress ulcer regimen in intact and neck-sham operated, but not in thyroidectomized rats without and with additional adrenal demedullation. Gastrin and glucagon were not correlated with calcemia during either stress alone or stress combined with intragastric Ca infusion. It is suggested that the development of gastric stress ulcerations can be prevented by a Ca-mediated release of endogenous calcitonin.
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PMID:Hypocalcemia during restraint stress in rats. Indication that gastric ulcer prophylaxis by exogenous calcium interferes with calcitonin release. 47 75


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