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)

Sequential determinations of glucose outflow and inflow, and rates of gluconeogenesis from alanine, before, during and after insulin-induced hypoglycemia were obtained in relation to alterations in circulating epinephrine, norepinephrine, glucagon, cortisol, and growth hormone in six normal subjects. Insulin decreased the mean (+/-SEM) plasma glucose from 89+/-3 to 39+/-2 mg/dl 25 min after injection, but this decline ceased despite serum insulin levels of 153+/-22 mul/ml. Before insulin, glucose inflow and outflow were constant averaging 125.3+/-7.1 mg/kg per h. 15 min after insulin, mean glucose outflow increased threefold, but then decreased at 25 min, reaching a rate 15% less than the preinsulin rate. Glucose inflow decreased 80% 15 min after insulin, but increased at 25 min, reaching a maximum of twice the basal rate. Gluconeogenesis from alanine decreased 68% 15 min after insulin, but returned to preinsulin rates at 25 min, and remained constant for the next 25 min, after which it increased linearly. A fourfold increase in mean plasma epinephrine was found 20 min after insulin, with maximal levels 50 times basal. Plasma norepinephrine concentrations first increased significantly at 25 min after insulin, whereas significantly increased levels of cortisol and glucagon occurred at 30 min, and growth hormone at 40 min after insulin. Thus, insulin-induced hypoglycemia in man results from both a decrease in glucose production and an increase in glucose utilization. Accelerated glycogenolysis produced much of the initial, posthypoglycemic increment in glucose production. The contribution of glycogenolysis decreased with time, while that of gluconeogenesis from alanine increased. Of the hormones studied, only the increments in plasma catecholamines preceded or coincided with the measured increase in glucose production after hypoglycemia. It therefore seems probable that adrenergic mechanisms play a major role in the initiation of counter-regulatory responses to insulin-induced hypoglycemia in man.
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PMID:The role of adrenergic mechanisms in the substrate and hormonal response to insulin-induced hypoglycemia in man. 0 91

Patients with inflammatory bowel disease (IBD) manifest growth failure which may antecede abdominal symptoms by some years. Eight of ten children with documented IBD had records of decreasing growth velocities. Investigation of growth hormone reserves showed excessive rather than impaired responses. Mean basal GH level was 6.2 +/- 0.75 (SEM) ng/ml. During sleep, the mean GH level rose to 26.0 +/- 4.7 ng/ml and following propranolol-glucagon stimulation, to 46.0 +/- 4.5 ng/ml. All values were significantly higher than levels obtained in a control population of 25 children investigated for short stature who were not GH deficient. The mean peak GH response following insulin in the IBD group (10.8 +/- 3.8 ng/ml), however, did not differ from the mean peak response in the control group (13.5 +/- 3.3 ng/ml). Growth failure in patients with IBD is not the result of GH deficiency and is not an irreversible phenomenon. On the contrary, judicious use of glucocorticoids aimed at the control of the disease usually produces compensatory growth acceleration ("catch-up growth").
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PMID:Basal and stimulated serum growth hormone concentrations in inflammatory bowel disease. 1 69

In order to study the oeffect of somatostatin on the endocrine pancreas directly, islets isolated from rat pancreas by collagenase were incubated for 2 hrs 1) at 50 and 200 mg/100 ml glucose in the absence and presence of somatostatin (1, 10 and 100 mg/ml) and2) at 200 mg/100 ml glucose together with glucagon (5 mug/ml), with or without somatostatin (100 ng/ml). Immunologically measurable insulin was determined in the incubation media at 0, 1 and 2 hrs. Insulin release was not statistically affected by any concentration stomatostatin. On the other hand, somatostatin exerted a significant inhibitory action on glucagon-potentiated insulin secretion (mean +/- SEM, mu1/2 hrs/10 islets: glucose and glucagon: 1253 +/- 92; glucose, glucagon and somatostatin: 786 +/- 76). The insulin output in th epresence of glucose, glucagon and somatostatin was also significantly smaller than in thepresence of glucose alone (1104 +/- 126) or of glucose and somatostatin (1061 +/- 122). The failure of somatostatin to affect glucose-stimulated release of insulin from isolated islets contrasts its inhibitory action on insulin secretion as observed in the isolated perfused pancreas and in vivo. This discrepancy might be ascribed to the isolation procedure using collagenase. However, somatostatin inhibited glucagon-potentiated insulin secretion in isolated islets which resulted in even lower insulin levels than obtained in the parallel experiments without glucagon. It is concluded that the hormone of the alpha cells, or the cyclic AMP system, might play a part in the machanism of somatostatin-induced inhibition of insulin release from the beta-cell.
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PMID:Somatostatin-induced inhibition of insulin secretion from isolated islets of rat pancreas in presence of glucagon. 16 38

Previous studies of the ability of the immature heart to respond to glucagon have yielded conflicting results. To test the possibility that the apparent discrepancies might be explained in part by species variability, isolated hearts of fetal mice and rats (13-22 days' gestational age) were studied under identical conditions in vitro. Changes in atrial rate and ventricular contractility were measured in spontaneously beating hearts exposed to glucagon, and activation of adenylate cyclase was assayed in cardiac homogenates. In mice of 16 days' gestational age or less, there was no change in heart rate in response to glucagon; at 17-18 days, minimal responsiveness was present; and after 19 days, 10muM glucagon caused an increase in spontaneous atrial rate of 30 +/- 4% (SEM) (P less than 0.001). Measurement of the extent and speed of volume displacement of the isotonically contracting hearts with a specially constructed capacitance transducer revealed that ventricular inotropic responsiveness also appeared after 17-19 days. Cardiac stores of glycogen were reduced in older hearts exposed to glucagon, but not in those aged less than 16 days. In contrast, glucagon failed to activate adenylate cyclase in homogenates of hearts of fetal mice at any age. Furthermore, glucagon failed to elicit an increase in the concentration of cyclic AMP in spontaneously beating hearts that developed tachycardia. Responses in hearts of fetal rats were distinctly different from those in mouse hearts: at no age was there any change in heart rate, strength of contraction, glycogen content, or adenylate cyclase activation. Thus, there are major species differences in cardiac pharmacological maturation. Although the mouse heart develops the ability to increase its rate and strength of contraction and to undergo glycogenolysis in response to glucagon well before birth, the rat heart does not. In addition, there is an apparent disparity in late fetal mouse hearts between the ability of glucagon to induce functional responses and its ability to stimulate adenylate cyclase and increase cyclic AMP levels. It is impossible, of course, to rule out absolutely the possibility that localized increases in a critical cyclic AMP pool were present but too small to measure in the entire tissue. Nevertheless, the most obvious interpretation of our results is that they are compatible with the hypothesis that glucagon may exert some of its hemodynamic effects independently from the adenylate cyclase-cyclic AMP system in the late-fetal mouse heart.
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PMID:Responsiveness to glucagon in fetal hearts. Species variability and apparent disparities between changes in beating, adenylate cyclase activation, and cyclic AMP concentration. 17 87

Increased glucagon (IRG) levels have been documented in liver cirrhosis, particularly associated with portal-systemic shunting. In spite of increased insulin (IRI) levels, IRI/IRG are reduced. This alteration has been proposed to have a pathogenic role in plasma aminoacid imbalance which seems to account for hepatic encephalopathy. We studied IRG and IRI/IRG in 13 controls and in 3 groups of cirrhotics, divided on the basis of their mental state. Glucagon was determined by means of 30 K Unger's antibody; insulin by a double antibody technique. Results are expressed in the table as means +/- SEM. (Formula: see text)A progressive increase in IRG secretion is present in cirrhotics and correlates with the mental state; IRI/IRG is not altered in cirrhosis until neurological distrubances are present. A relative fall in IRI which can no more balance the increasing IRG values characterizes hepatic encephalopathy.
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PMID:The role of insulin and glucagon in the plasma aminoacid imbalance of chronic hepatic encephalopathy. 38 61

The absorption of insulin and its glucose-lowering effect were compared after the administration of crystalline insulin by sc, im, and iv routes in 29 obese and 10 lean nonketotic diabetic patients, none of whom had consciously received insulin previously. Each of the patients received insulin in a dose of 0.1 U/kg BW by the im, sc, and iv routes in a randomized fashion on 3 different days. Plasma glucose, immunoreactive insulin (IRI), and immunoreactive glucagon (IRG) were measured at intervals over the first 4 h. The t1/2 (mean +/- SEM) after iv administration of insulin in obese and lean diabetics was, respectively, 5.3 +/- 0.2 and 4.8 +/- 0.4 min; these were not significantly different. Intravenous injection produced its highest level of IRI in 2 min in both groups. Thereafter, a rapid drop was observed with return to the basal level by 90 min. Equivalent amounts of im and sc insulin produced a maximal increase in plasma IRI at 60 min in both groups. Plasma IRI after iv insulin injection was significantly higher than after sc and im insulin injections at 10 and 20 min (P less than 0.001) and significantly lower than the im and sc groups at 60, 90, 120, 150, 180, 210, and 240 min (P less than 0.001). After iv insulin, plasma glucose at 30, 40, 50, and 60 min was significantly lower than after im and sc insulin (P less than 0.001), but over the 4-h study period, the glucose-lowering effect and the area under the curves for glucose response to IRI by the three routes were the same in both lean and obese diabetic subjects. The mean basal IRI in lean patients was 18 +/- 4 microU/ml, which was significantly lower (P less than 0.05) than in obese patients (26 +/- 2 microU/ml). No significant difference was observed in fasting IRG in lean (96 +/- 12 pg/ml) vs. obese (108 +/- 10 pg/ml) patients. No significant increase in IRG was noted with equivalent amounts of sc, im, and iv injection in the lean and obese patients. These studies demonstrated that although iv injection of insulin produces a more rapid initial decline in plasma glucose, the overall glucose-lowering effect by insulin given iv, im or sc is similar in nonketotic lean or obese diabetic subjects.
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PMID:Glucose-lowering effect of insulin by different routes in obese and lean nonketotic diabetic patients. 40 Jul 13

Hypoglycemia is known to stimulate human pancreatic polypeptide (hPP) secretion. To explore further the relationship between glucose availability and hPP release, we have examined the effect of tissue glucopenia induced by 2-deoxy-D-glucose (2-DG) on hPP plasma levels in normal subjects. As this glucose analogue activates the autonomic nervous system, we have also studied the influence of prior atropinization upon the hPP response to 2-DG. Moreover, we have tested the effects of iv epinephrine and norepinephrine on plasma hPP concentrations. Circulating glucagon was also measured. After the iv infusion of 2-DG (50 mg/kg), plasma hPP increased steeply from a fasting value of 104 +/- 24 pg/ml (SEM) to a peak of 2175 +/- 639 pg/ml at 45 min (P less than 0.01) and remained significantly elevated throughout the test. In contrast, prior injection of atropine (1 mg iv) lowered basal hPP levels and reduced conspicuously the hPP response to 2-DG. Epinephrine administration (6 micrograms/min for 60 min) did not significantly modify plasma hPP concentrations. However, 2 h after epinephrine withdrawal, circulating hPP showed a brisk elevation coinciding with the decline of glycemia to subbaseline values. During norepinephrine infusion (6 micrograms/min for 60 min), only a minor and transient increase of plasma hPP was found. Plasma glucagon rose significantly after 2-DG infusion, but this response was virtually absent in the atropine experiment. Whereas the well known glucagon tropic activity of epinephrine was evidenced, norepinephrine failed to exert an obvious effect on glucagonemia. Our data demonstrate that 2-DG induces a powerful stimulation of hPP secretion in normal subjects and suggest that this action is mediated in part, if not entirely, by the parasympathetic nervous system. On the other hand, a major role of the sympathoadrenal system in response of hPP to 2-DG or to hypoglycemia does not seem probable. Finally, the hyperglucagonemic effect of 2-DG seems also to be dependent on cholinergic transmission.
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PMID:Stimulation of pancreatic polypeptide and glucagon secretion by 2-deoxy-D-glucose in man: evidence for cholinergic mediation. 40 Jul 18

Intravenous hyperalimentation allows complete nutrition and anabolism in patients who cannot be fed by the oral route. However, several complications have been reported, e.g. septicaemia and hyperglycaemina. In 51 intensive-care patients receiving hyperalimentation, 18% were found to be hyperglycaemic in spite of insulin administration. Hyperglycaemia was frequently associated with stress. In 8 patients undergoing major surgery, which was chosen as a stress model, decreased insulin and increased glucagon, growth hormone and cortisone levels were observed. These findings could explain stress-induced glucose intolerance. In a further experiment, 8 intensive-care patients were given alternative intravenous feedings with either 600g of a mixture of glucose, fructose and xylitol in a ration of 1:2:1 or 600g glucose per day. During both regimens insulin administration was required in 4 patients, but the insulin dosage was lower with the mixture. Plasma glucose during glucose infusion was 205+/-25mg/100ml(M+/-SEM) and the sum of plasma glucose, fructose and xylitol during infusion of the mixture was 176+/-33mg/100ml, the difference being of borderline significance (p less than 0.05). The advantages and disadvantages of infusable substrates are summarized on the basis of the available literature and it is concluded that, in general, glucose is preferable. However, if hyperglycaemia is difficult to control, partial replacement of glucose by glucose substitutes or fat emulsions may be advantageous. A routine infusion programme for central venous feeding is suggested. Causes and prevention of side-effects are reviewed. In many patients receiving central venous nutrition less hazardous and less expensive methods could be used such as nasogastric tube feeding, elemental diet or peripheral venous nutrition.
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PMID:[Parenteral hyperalimentation (author's transl)]. 40 48

The composition, half life and hyperglycemic action of the porcine gastrointestinal glucagon-like immunoreactive materials were examined. Glucagon immunoreactivity (GI) measured using specific antiglucagon serum was more abundunt in the extract from the gastric fundus than in the one from the small intestine. When the extract from the gastric fundus was injected in dogs, the half life (T1/2) of total glucagon-like immunoreactivity (total GLI) measured using nonspecific antiglucagon serum was 9.5 +/- 1.1 min (mean +/- SEM), which was longer than that of crystalline pancreatic glucagon, 3.4 +/- 0.2 min, but shorter than that of the extract from the small intestine, 15.9 +/- 1.3 min. On the other hand, T1/2 for GI from the gastric fundus was 5.1 +/- 0.9 min, which was not significantly different from that of crystalline pancreatic glucagon. Blood sugar levels were significantly increased from the basal by 25 +/- 4 mg/100 ml at 10 min and 19 +/- 4 mg/100 ml at 15 min following an injection of the extract from the gastric fundus, but such a change in blood sugar levels was not demonstrated when the extract from the small intestine was injected. These results suggest that GI of the gastric fundus is close to pancreatic glucagon in respect of its metabolism and hyperglycemic activity.
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PMID:Half life of gastrointestinal glucagon-like immunoreactive materials. 43 1

Glucogon immunoreactivity (IRG) was measured in plasma of duodenopancreatectomized subjects with a nonspecific (K-4023) and a specific (30-K) glucagon antiserum. After an overnight fast, plasma IRG (K-4023) was significantly (P < 0.05) higher in the subjects without pancreas, averaging 782+/-79 (SEM) pgeq/ml, than in the controls (482+/-80 pgeq/ml). IRG (30-K) of 162+/-68 pg/ml did not change during an infusion of arginine (450 mg/kg per 40 min). Insulin deprivation during 3 d in one patient did not restore the IRG response to arginine as reported in depancreatized dogs.Bio-Gel P-30 column chromatography revealed that virtually all IRG (30-K) measured in whole plasma was of different molecular weight than glucagon, and primarily of a mol wt >/= 40,000. Intravenous arginine did not significantly alter the chromatographic pattern of these plasmas. Thus, as postulated by others, duodeno-pancreatectomized humans have virtually no circulating 3,500-dalton glucagon. Hence, the presence of 3,500-dalton glucagon in plasma is not a condition for the diabetic state. It might, nevertheless, when present in normal or excessive amounts, worsen the metabolic state of diabetic patients. Among 14 amino acids measured in plasma of these patients, the concentrations of alanine, serine, ornithine, and arginine were significantly (P < 0.05) elevated to approximately twice that of normal: alanine and serine are both substrates for gluconeogenesis, whereas ornithine and arginine are involved in the formation of urea, the second product of hepatic gluconeogenesis. As the concentrations of branched chain amino acids were not grossly altered, it is hypothesized that this amino acid pattern is a consequence of glucagon deficiency rather than secondary to the diabetic state of these patients.
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PMID:Glucagon immunoreactivities and amino acid profile in plasma of duodenopancreatectomized patients. 44 30


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