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)

Infusion of somatostatin, an inhibitor of glucagon secretion, in insulin-dependent diabetics resulted in a 75-100% reduction in the blood-glucose rise after oral glucose administration, but did not improve intravenous glucose tolerance. Somatostatin reduced blood-xylose levels by 50-90% after ingestion of this pentose and delayed the peak increment in blood-xylose by 1-2 h. Similar effects on blood-xylose levels and a 30% reduction in splanchnic blood-flow were observed in normal subjects during infusion of somatostatin. Glucagon administration (3 ng per kg per min) or intraduodenal administration of xylose did not reverse somatostatin's effect on xylose tolerance. Somatostatin reduces postprandial hyperglycaemia in diabetes primarily by decreasing and/or delaying carbohydrate absorption rather than enhancing carbohydrate disposal. This effect may be mediated, in part, but a reduction in splanchnic blood-flow. These findings indicate that postprandial hyperglycaemia in diabetes is due primarily to insulin deficiency rather than glucagon excess.
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PMID:Influence of somatostatin on carbohydrate disposal and absorption in diabetes mellitus. 6 40

Recent data seem to support a tubular defect as the mechanism of the elevated renal clearance of amylase relative to creatinine in acute pancreatitis. Glucagon has been proposed by some to be an important factor in this phenomenon. To examine the role of glucagon as this "tubular dysfunction factor", we investigated the effect of intravenously infused glucagon on the fractional excretion of amylase and the tubular handling of a low molecular weight protein, beta2 microglobulin, in normal, healthy volunteers. At glucagon levels far in excess of those seen in pancreatitis, the clearance ratio of beta2 microglobulin relative to creatinine increased, whereas the clearance ratio of amylase relative to creatinine did not increase above the normal range. The dissociation between beta2 microglobulin clearance and amylase clearance allows one to question the theory that tubular dysfunction is the mechanism of the elevated renal clearance of amylase relative to creatinine in acute pancreatitis. Glucagon does not appear to be the sole factor responsible for the elevation of renal clearance of amylase relative to creatinine in acute pancreatitis.
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PMID:Effect of glucagon infusion on the renal clearance of amylase relative to creatinine. 8 90

Porcine vasoactive intestinal peptide stimulated adenosine 3':5'-monophosphate (cyclic AMP) production in rat intestinal epithelial cells. The stimulation was dependent on time and temperature and was potentiated by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine. Under optimal conditions (at 15 degrees C, with 0.2 mM 3-isobutyl-1-methylaxanthine, at a cell concentration up to 18 microgram DNA/ml), the cyclic AMP production produced by vasoactive intestinal peptide was constant for 10 min and stopped after 15 min incubation, at either low (1 nM) or high (30 nM) concentration of the peptide. This plateau effect was demonstrated not to be due to an inactivation of vasoactive intestinal peptide in the medium nor to an alteration of receptors for the peptide. Cyclic AMP production was sensitive to a concentration as low as 0.1 nM vasoactive intestinal peptide. Maximal stimulation of cyclic AMP levels by vasoactive intestinal peptide was observed with 30 nM vasoactive intestinal peptide and represented an 11-fold increased above basal. The dorse-response curve was monophasic with a Km of 2.3 x 10(-9) M. No cooperative effects were detected by Hill analysis. The positive non-linear relationship observed between stimulation of cyclic AMP production and occupancy of binding site was not time-dependent as indicated by experiments performed after 15, 45 and 120 min incubation. Maximal and half-maximal responses were obtained at about 70% and 7% occupation of binding sites, respectively. Chicken vasoactive intestinal peptide and porcine secretin were agonists of porcine vasoactive intestinal peptide with a 6-times and a 120-times lower potency, respectively. Among secretin analogs that were found to have low affinity for vasoactive intestinal peptide binding sites, [4-alanine, 5-valine]secretin, that resembles vasoactive intestinal peptide at the first seven amino acids at the N-terminal end, was a partial agonist of vasoactive peptide at the first seven amino acids at the N-terminal end, was a partial agonist of vasoactive intestinal peptide and others failed to stimulate cyclic AMP production. Glucagon (10microM), gastric inhibitory peptide (0.1 microM), substance, P, neurotensin, octapeptide of cholecystokinin, bovine pancreatic polypeptide, human gastrin I with leucine at residue 15, Leu-enkephalinand somatostatin (1 microM) did not alter cyclicAMP levels. Non-peptide mediators such as dopamine, serotonin, acetylcholine and histamine, tested at 10 microM, were also ineffective. Prostaglandins E2, E1 and isoproterenol, tested at 10 microM, induced an increase of cyclic AMP levels above basal but were 9.5, 13.7 and 17.5 times less efficient than vasoactive intestinal peptide, respectively. Thus vasoactive intestinal peptide is a unique stimulus of cyclic AMP production in rat intestinal epithelial cells.
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PMID:Interaction of vasoactive intestinal peptide with isolated intestinal epithelial cells from rat. 2. Characterization and structural requirements of the stimulatory effect of vasoactive intestinal peptide on production of adenosine 3':5'-monophosphate. 8 68

Radioimmunological method was applied to the study of glucagon content in patients with diabetes mellitus of different severity and duration of the disease. Glucagon level on fasting stomach in patients with diabetes at the state of compensation failed to differ from that in healthy persons. But in decomensated disease with the ketoacidosis phenomena there was a sharp elevation of glucagon content with restoration to the normal after the compensation was reached. In patients with diabetes mellitus complicated by diabetic retinopathy blood glucagon content failed to correlate with the incidence of retinopathy. However, there was a direct relationship between the incidence of retinopathy and the duration of the disease. In adipose diabetic patients glucagon content was elevated, but this rise was insignificant in comparison with healthy persons.
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PMID:[Nature of changes in glucagon secretion in diabetes mellitus]. 9 60

An ultrasonic window to the upper abdomen is creasted by (a) filling the fasting stomach with methylcellulose suspension, (b) administering glucagon intravenously, and (c) examining the patient prone. Glucagon relaxes the gastric musculature and the prone position allows the stomach gas to rise to the fundus. This enables assessment of the relationships of the stomach to adjacent structures and permits display of structures forming the stomach bed. The equipment used was a commercially available water-delay system with wide-aperture focused transducers. The system gives good resolution and allows the gastric musculature to be distinguished from the mucosa and its overlying mucus.
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PMID:The liquid-filled stomach--an ultrasonic window to the upper abdomen. 10 95

The binding and degradation of insulin and glucagon to kidney cell membranes was examined. Time- and temperature-dependent specific binding of [125I]iodo-insulin to kidney cell membranes was demonstrated. The membranes also degraded insulin in a time-, temperature-, and protein concentration-dependent manner. The apparent Km of the degradation was 2.7 x 10(-7) M. Glucagon degradation by the kidney membranes was extremely active. Per milligram of protein the kidney membrane was over 20 times as active as the liver membrane. Even at 4 C, significant glucagon degradation occurred. Because of this very active degradation, glucagon binding could not be accurately assessed. The kidney glucagon-degrading activity was inhibited by glutahione and EDTA but unaffected by N-ethylmaleimide, ACTH, or insulin, all potent inhibitors of liver glucagon degradation. The apparent Km for glucagon degradation by the kidney, however, was essentially identical with that for the liver, 2.4 x 10(-6) M.
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PMID:Insulin and glucagon binding and degradation by kidney cell membranes. 10 82

TRH has been shown to be present in the pancreas. To examine a possible role for TRH in the control of endocrine pancreatic function, we have studied the effects of TRH on the isolated perfused rat pancreas preparation. Arginine caused release of TRH from the preparation. The mean maximum TRH peak was 85 +/- 12 pg/ml and occurred later than the first phase of glucagon release. Glucagon (2000 pg/ml) did not release TRH from the preparation. There was no detectable basal release of TRH. Glucose did not stimulate release of TRH from the pancreas preparation. TRH (10 ng/ml) by itself had no effect on insulin or glucagon release. TRH enhanced arginine-induced glucagon release; mean summated glucagon was 8228 +/- 1138 (SE) pg/ml compared to controls (4530 +/- 447 pg/ml; P less than 0.01). There was a tendency for TRH to enhance second phase glucose-induced insulin release. Pancreatic physiology is in part regulated by locally acting hormones and TRH may be one of these hormones.
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PMID:The effects of thyrotropin-releasing hormone on the endocrine pancreas. 10 72

Combined Glucagon-Propranolol test used for study of growth hormone is advantages. The combined administration of TRH and LHRH is possible. In 53 children, the hormone responses (GH, TSH, FSH, LH and prolactin) were studied. This combined test allows the rapid assessment of anterior pituitary function.
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PMID:[Combined test for assessment of anterior pituitary function using glucagon-propranolol, TRH and LHRH (author's transl)]. 11 72

Glibenclamide has been shown to stimulate an insulin releasing factor in the duodenum. The possibility that this effect is of importance in its hypoglycaemic action was investigated by studying the effect of galactose on insulin release before and after treatment with glibenclamide; galactose stimulates insulin release when given orally but has no effect when given parenterally; thus its ability to release insulin appears to reside in an action on a gut factor. Measurements of plasma glucose, insulin and glucagon were made on twelve maturity onset diabetic patients following an oral glucose tolerance test and an oral galactose tolerance test before and after one week of treatment with glibenclamide. Glibenclamide significantly reduced the blood glucose levels. Both basal insulin and basal glucagon levels were unchanged. The insulin response to oral glucose was enhanced. Glucagon levels before treatment did not suppression of glucagon levels. Galactose stimulated insulin release but insulin levels before and after treatment were identical. An effect of glibenclamide on gut insulin releasing activity was not demonstrated but the galactose tolerance test provides a useful technique by which to examine the enteroinsular axis.
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PMID:The effect of glibenclamide treatment on the insulin and glucagon responses to oral glucose and galactose in maturity onset diabetics. 11 30

Glucose tolerance and insulin and glucagon secretion were examined sequentially during 6 months of calorie and carbohydrate restriction in an obese, recent-onset, ketosis-resistant diabetic adult. The subject was then followed for 9 additional months, during which some weight was regained. Fasting plasma glucose levels returned to normal after 6 week of calorie restriction and remained normal during periods of carbohydrate refeeding. Normalization of 2-h plasma glucose concentrations after a standard oral carbohydrate load required 5 months, and glucose disposal after an iv glucose load did not return to normal until the end of the study. Insulin secretion in response to oral glucose reached maximal levels during the first months of weight reduction and then decreased as glucose tolerance continued to improve. Acute phase insulin release in response to iv glucose gradually increased throughout the study. Glucagon stimulation by iv arginine and suppression by iv glucose also returned to normal levels slowly over several months. Abnormalities in glucose tolerance and glucoregulatory hormone secretion of ketosis-resistant diabetes are totally reversible with prolonged dietary therapy. Reduction in tissue resistance to the action of insulin also appeared to be of major importance in the recovery of normal glucose tolerance in this subject.
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PMID:Normalization of insulin and glucagon secretion in ketosis-resistant diabetes mellitus with prolonged diet therapy. 11 19


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