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 ability of the insulin-induced phospho-oligosaccharide to stimulate amino acid transport was studied in isolated rat hepatocytes. At low alpha-aminoisobutyric acid concentrations (0.1 mM), both 100 nM-insulin and 10 microM-phospho-oligosaccharide doubled amino acid uptake after 2 h of incubation. This stimulation was prevented by 0.1 mM-cycloheximide or 5 micrograms of actinomycin D/ml, indicating that the phospho-oligosaccharide, like insulin, was acting via the synthesis of a high-affinity transport component. The effects of the phospho-oligosaccharide and of insulin were blocked by Ins2P (2.5 mM), but not by myo-inositol, inositol hexaphosphoric acid or several monosaccharides such as mannose, glucosamine and galactose. Both the temporal effect on amino acid entry and the extent of stimulation of this process by the phospho-oligosaccharide indicate that this molecule mimics, and may mediate, some of the long-term actions of insulin. However, the effects of phospho-oligosaccharide and insulin were not exactly the same, since the effect of insulin, but not of the phospho-oligosaccharide, was additive with that of glucagon.
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PMID:Insulin-induced phospho-oligosaccharide stimulates amino acid transport in isolated rat hepatocytes. 218 44

The perioperative blood glucose regulatory response was compared in 20 healthy children (aged 1-5 yr) presenting for minor surgery and allocated randomly to either a fasted or a glucose group. All children received a milk feed at midnight. The fasted group received no oral intake thereafter, whereas the glucose group received 5% dextrose water 10 ml kg-1 orally about 4 h before operation. The mean plasma glucose concentrations in the two groups were similar before operation and were within normal limits. The pattern of change in the concentrations of plasma glucose, insulin, cortisol, growth hormone and glucagon were also similar between the two groups. Ten percent of patients in the fasted group and 33% in the glucose group had gastric aspirates in excess of 0.4 ml kg-1. The pH of all gastric samples was less than 2.5. The results suggest that healthy preschool children were able to maintain glucose homeostasis after 8 h of fasting. Feeding within 4-6 h before surgery may increase the risk of pulmonary aspiration.
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PMID:Paediatric glucose homeostasis during anaesthesia. 218 14

A randomised controlled trial of insulin and glucagon infusion was carried out in 18 patients in grade III or IV coma from fulminant hepatic failure due to viral or drug-induced hepatic necrosis to see whether mortality could be reduced by stimulating hepatic regeneration. Nine patients received a continuous infusion of insulin 3 U/h and glucagon 200 micrograms/h made up in 5% dextrose containing 1% human albumin solution (HAS) while controls received 5% dextrose and HAS alone. Baseline plasma insulin and glucagon levels were comparably raised in both groups and, on infusion, rose significantly higher in the insulin- and glucagon-treated patients compared to controls. Two control and one treated patient recovered. Median survival time from enrolment to death was similar for insulin- and glucagon-treated patients and controls--2 and 3 days, respectively. Insulin and glucagon therapy did not enhance hepatic synthetic function, as measured by a fall in prothrombin time or a rise in alpha-fetoprotein; nor did it stimulate hepatic regeneration, only one patient in each group showed histological evidence of hepatic regeneration at post-mortem.
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PMID:Failure of insulin and glucagon infusion to stimulate liver regeneration in fulminant hepatic failure. 219 8

Incubation of rat adipocytes with 1 microM glucagon plus adenosine deaminase (5 micrograms/ml) inhibited maximally insulin-stimulated 3-O-methyl-D-glucose (MeGlc) transport by approximately 70%, concomitant with 30% and 55% decreases in insulin binding and cellular ATP, respectively. In contrast, under conditions where cellular ATP levels are well preserved (i.e. high albumin concentration in the medium), the inhibition of transport was reduced to about 30%, but that of insulin binding was not. Because depletion of the cellular ATP level by more than 60% by metabolic inhibitors induced 40% or more inhibition of insulin-stimulated MeGlc transport, the greater inhibition of the transport with the low albumin concentration appears to be caused in part by the secondary effect of ATP loss. The relationship between the amount of cell-bound insulin and hormone-stimulated transport activity showed that glucagon does not modulate insulin action at the step of insulin binding to its receptors. Furthermore, glucagon suppressed insulin-stimulated MeGlc transport, mainly through an attenuation of the hormone-induced increase in maximum velocity. The data show that glucagon modulates the process of signal transduction of insulin action. However, the possibility that glucagon directly modulates the process of translocation or the intrinsic activity of the glucose transporters cannot be eliminated.
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PMID:Glucagon inhibits insulin activation of glucose transport in rat adipocytes mainly through a postbinding process. 220 31

Female Wistar rats weighing 217 g were subjected to two types of surgical stress: uncomplicated (hysterectomy) and complicated (spleen and uterus ligated, crushed, and left in situ). Liver function as assessed by amino-N conversion was measured as the capacity for urea-N synthesis preoperatively (control animals) and on Days 1, 3, and 6 postoperatively. Uncomplicated surgery transiently increased the capacity for urea-N synthesis by 30% the first postoperative day (P less than 0.001). Complicated surgery decreased the capacity for urea-N synthesis to 55% throughout the investigation period (P less than 0.001). This was not due to a general change in liver mass since galactose elimination capacity remained constant. The increase in the capacity for urea-N synthesis after uncomplicated surgery is probably due to glucagon since plasma glucagon increased whereas plasma insulin and blood glucose remained unchanged after amino acid loading. The persistent decrease in the capacity for urea-N synthesis in complicated surgery is not due to changes in these regulators: glucagon increased, insulin decreased, and the rats were hypoglycemic. All changes are expected to increase the capacity for urea-N synthesis. The mechanism for the emergence of these two distinct metabolic patterns is not known. The phenomenon is probably important for interpretation of metabolic data on clinical stress.
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PMID:Contradictory effects of uncomplicated versus complicated abdominal surgery on the hepatic capacity for urea synthesis in rats. 220 48

We used positron emission tomography (PET) to study the effects of mild hypoglycemia on cerebral glucose uptake and metabolism. Nine healthy men were studied under basal saline-infusion conditions, and during euglycemic and hypoglycemic clamp studies. Insulin was infused at the same rate (1 mU.kg-1.min-1) in both clamp studies. In euglycemic clamp studies, glucose was infused at a rate sufficient to maintain the basal plasma glucose concentration, whereas in hypoglycemic clamp studies, the glucose infusion rate was reduced to maintain the plasma glucose at 3.1 mM. Each study lasted 3 h and included a 30-min baseline period and a subsequent 150-min period in which insulin or glucose was administered. Blood samples for measurement of insulin, glucose, cortisol, growth hormone, and glucagon were obtained at 20- to 30-min intervals. A bolus injection of 5-10 mCi [18F]-2-deoxy-2-fluoro-D-glucose (2-DFG) was administered 120 min after initiation of the study, and plasma radioactivity and dynamic PET scans were obtained at frequent intervals for the remaining 40-60 min of the study. Cerebral regions of interest were defined, and concentrations of radioactivity were calculated and used in the three-compartment model of 2-DFG distribution described by Sokoloff. Glucose levels were similar during saline-infusion (4.9 +/- 0.1 mM) and euglycemic clamp (4.8 +/- 0.1 mM) studies, whereas the desired degree of mild hypoglycemia was achieved during the hypoglycemic clamp study (3.1 +/- 0.1 mM, P less than 0.05). The insulin level during saline infusion was 41 +/- 7 pM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Change in hexose distribution volume and fractional utilization of [18F]-2-deoxy-2-fluoro-D-glucose in brain during acute hypoglycemia in humans. 222 24

The structure-activity relationship of sugars inducing secretion of glucagon-like peptide-1 from the gut was examined using intestinal loops prepared from the terminal portion of the ileum of dogs. The plasma glucagon-like peptide-1 concentration in a mesenteric vein draining only the looped region of the intestine was increased after infusion of 139 mmol/l solutions of D-glucose, D-galactose, D-glucuronic acid, 3-0-methyl-D-glucose, maltose, sucrose or maltitol into the intestinal lumen, but not after infusion of solutions of D-fructose, D-fucose, D-mannose, D-xylose or lactose. The increases in plasma glucagon-like peptide-1 concentration correlated with the corresponding increases in glucagon-like immunoreactivity induced by these sugars. The plasma glucose level of the regional mesenteric vein increased significantly from the basal level after instillation of D-glucose, but not after instillation of other sugars. It is suggested that cells of the gut have a glucose sensor for release of products of the glucagon gene and that this sensor has specific steric requirements. The sugars that induced glucagon-like peptide-1 release share the molecular features of electron density near C(6), an equatorial hydroxyl at C(2), and an axial hydroxyl at C(1), which could account for their recognition by the glucose sensor to initiate the releases of glucagon-like peptide-1 and glucagon-like immunoreactivity.
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PMID:Relationship between molecular structures of sugars and their ability to stimulate the release of glucagon-like peptide-1 from canine ileal loops. 223 92

Using the test of glucagon load and the test of galactose tolerance the usefulness was compared of both these carbohydrate tests in the clinical diagnosis of cirrhosis. The studied group comprised 30 patients with cirrhosis divided into two groups depending on the stage of the disease, and 21 women with spastic colitis serving as a control group. Both tests were found to be useful in the diagnosis of cirrhosis. The results of these tests were statistically significantly different from those in the control group which could be demonstrated as different shapes of blood glucose curves. Moreover, range values could be proposed for blood glucose levels characteristic of cirrhosis and criteria could be established using these tests for differentiating compensated against decompensated cirrhosis.
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PMID:[Comparison of the value of the glucagon test and galactose tolerance test in the clinical diagnosis of cirrhosis]. 236 89

Hypoglycaemia remains a serious and much feared complication of insulin therapy. In this study, patients attending an accident and emergency department in hypoglycaemic coma were randomized to treatment with either intravenous dextrose (25g) or intramuscular glucagon (1mg), administered into the right thigh. Restoration of normal conscious level was slower after glucagon than dextrose (9.0 vs 3.0 min, P less than 0.01), although the average duration of hypoglycaemic coma was 120 min. Two patients in the glucagon-treated group, who failed to show satisfactory recovery after 15 min, required additional treatment with intravenous dextrose. On questioning following recovery, all except two patients reported loss of awareness of the onset of hypoglycaemia Intramuscular glucagon is valuable in the treatment of severe hypoglycaemia outwith hospital and, although the slightly slower and less predictable recovery may appear to make it a less attractive option than intravenous dextrose in the accident and emergency department, this must be balanced against the advantages of ease of administration and a lower incidence of serious adverse effects.
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PMID:Comparison of intramuscular glucagon and intravenous dextrose in the treatment of hypoglycaemic coma in an accident and emergency department. 239 Jan 57

The secretory behavior of insulin- and glucagon-producing cells was found to be perturbed in isolated perfused pancreases removed from rats infused with hypertonic solutions of glucose for 48 hours. The anomalies included a high basal release of insulin and a paradoxical increase in insulin output and decrease in glucagon release in response to a fall in D-glucose concentration. Likewise, in isolated islets prepared from the glucose-infused rats, L-arginine or theophylline stimulated insulin release at a low ambient concentration of D-glucose, at variance with the situation found in islets removed from normal rats. These secretory perturbations could not be attributed to any obvious defect in either the transport of D-glucose into islet cells or its further utilization and oxidation, but coincided with the abnormal accumulation of glycogen in the B-cell. It is proposed that the latter anomaly may play a role in the altered dynamics of insulin release found in animals or patients with long-term hyperglycemia.
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PMID:Perturbation of pancreatic islet function in glucose-infused rats. 240 23


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