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 insulin and glucagon on liver cell volume and proteolysis were studied in isolated perfused rat liver. The rate of proteolysis was assessed as [3H]leucine release from single-pass-perfused livers from rats which had been prelabelled in vivo by intraperitoneal injection of [3H]leucine. The intracellular water space was determined from the wash-out profiles of simultaneously added [3H]inulin and [14C]urea. In normo-osmotic (305 mosM) control perfusions the intracellular water space was 548 +/- 10 microliters/g wet mass (n = 44) and was increased by 16.5 +/- 2.6% (n = 6), i.e. by 85 +/- 14 microliters/g, after hypoosmotic exposure (225 mosM). Glucagon (0.1 microM) decreased the intracellular water space by 17 +/- 4% (n = 4), whereas insulin (35 nM) increased the intracellular water space by 9.3 +/- 1.4% (n = 15). Also, in isolated rat hepatocyte suspensions insulin (100 nM) caused cell swelling by 10.7 +/- 1.8% (n = 16), which was fully reversed by glucagon. In perfused liver, insulin-induced cell swelling was accompanied by a hepatic net K+ uptake (4.5 +/- 0.2 mumol/g) and an inhibition of proteolysis by 21 +/- 2% (n = 12); further addition of glucagon led to a net K+ release of 3.8 +/- 0.2 mumol/g (n = 7) and fully reversed the insulin effects on both cell volume and proteolysis. Similarly, insulin-induced cell swelling and inhibition of proteolysis were completely antagonized by hyperosmotic (385 mosM) cell shrinkage. Furthermore, cell swelling and inhibition of proteolysis after hypo-osmotic exposure or amino acid addition were reversed by glucagon-induced cell shrinkage. There was a close relationship between the extent of cell swelling and the inhibition of proteolysis, regardless of whether cell volume was modified by insulin, glucagon or aniso-osmotic exposure. The data show that glucagon and insulin are potent modulators of liver cell volume, at least in part by alterations of cellular K+ balance, and that their opposing effects on hepatic proteolysis can largely be explained by opposing effects on cell volume. It is hypothesized that hormone-induced alterations of cell volume may represent an important, not yet recognized, mechanism mediating hormonal effects on metabolism.
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PMID:Regulation of liver cell volume and proteolysis by glucagon and insulin. 189 64

Intake of naftusia mineral water influences insulin, glucagon and gastrin secretion measured in patients with chronic acalculous cholecystitis in the following manner: initial low insulin and glucagon, normal gastrin levels rise; initial elevated gastrin and normal glucagon lower at the start of the treatment. The course of naftusia crenotherapy resulted in adaptation to water intake as evidenced by normalization of high gastrin, low glucagon levels in minimal rise of insulin.
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PMID:[The effect of a course of naftusia water intake on the gastroenteropancreatic endocrine system]. 192 98

The net release of insulin, glucagon and somatostatin by the portal-drained viscera (PDV) and their net uptake by the liver in response to 3-d abomasal infusions of casein were measured in seven multicatheterized beef steers. The steers were fed 4.3 kg DM/d of a high-concentrate diet in 12 equal meals (13.1 Mcal ME/d and 95 g N/d). In two separate experiments, the abomasal infusion of 300 g casein/d (300C) or 150 g casein/d (150C) was compared to a water infusion. Plasma flow was measured by indicator dilution and net flux by venoarterial concentration difference x plasma flow. Arterial plasma concentrations of insulin were increased (P less than .02) by either 300C or 150C. The 300C increased (P less than .03) PDV insulin release but did not affect hepatic uptake, resulting in an increased (P less than .03) total splanchnic (TSP) insulin flux. The 300C increased (P less than .05) plasma concentrations of glucagon as the result of decreased (P less than .06) hepatic extraction ratio and not as the result of increased portal release. The portal and hepatic flux of somatostatin measured as somatostatin-like immunoreactivity (SLI) were highly variable and not affected by casein infusions. Arterial plasma concentrations of somatomedin-C were not responsive to abomasal casein infusions. The abomasal infusion of 300C resulted in increased plasma concentrations of insulin via increased PDV release and increased plasma glucagon via decreased hepatic extraction ratio.
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PMID:The effects of abomasal casein infusions in growing beef steers on portal and hepatic flux of pancreatic hormones and arterial concentrations of somatomedin-C. 200 31

The use of a high content of acetic acid as mobile phase additive for the reversed-phase high-performance liquid chromatography (RP-HPLC) of several proteins and extracts of biological tissues was evaluated for a divinylbenzene (DVB)-based stationary phase, and the separations obtained with acetic acid gradients in acetonitrile, isopropanol or water were compared with classical polypeptide RP-HPLC on silica C4 with trifluoroacetic acid (TFA)-acetonitrile. The separation patterns for recombinant derived interleukin-1 beta (IL-1 beta) on the C4 column eluted with TFA-acetonitrile and the DVB column eluted with acetic acid-acetonitrile were similar, but only the polymeric column was able to separate the components present in an iodinated IL-1 beta preparation. Neither eluent had any harmful effect on the biological activity of IL-1 beta isolated after RP-HPLC. Several standard proteins could be separated when the polymeric column was eluted with acetic acid gradients in acetonitrile, isopropanol or water and, although the separation efficiency with acetic acid in water was lower than that in combination with classical organic modifiers, insulin, glucagon and human growth hormone (hGH) were eluted as sharp, symmetrical peaks. The recoveries of insulin and hGH were comparable for all three mobile phases (80-90%). The separation patterns obtained from a crude acetic acid extract of a normal and a diabetic, human pancreas analysed using acetic acid gradients with or without organic modifiers were found to be similar and comparable to those obtained on a silica C4 column eluted with an acetonitrile gradient in TFA. The principal differences resulted from the use of different UV wavelengths (215 nm for TFA-acetonitrile, 280 nm for acetic acid). Acetic acid extracts of recombinant derived hGH-producing Escherichia coli were separated on the DVB column eluted with an acetic acid gradient in water. Although the starting material was a highly complex mixture, the hGH isolated after this single-step purification was surprisingly pure (as judged by sodium dodecyl sulphate-polyacrylamide gel electrophoresis). Consequently several (pure) polypeptides and complex biological samples were separated on a polymeric stationary phase eluted with acetic acid gradients in water without the use of organic modifiers.
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PMID:Alternative mobile phases for the reversed-phase high-performance liquid chromatography of peptides and proteins. 205 Jul 79

The combination of a divinylbenzene-based reversed-phase (RP) column and acetic acid gradients in water as mobile phase described in the accompanying paper was used for characterizing the extractable polypeptides from the normal and the diabetic human pancreas. The pancreas was lyophilized, minced and extracted three times in 3 M acetic acid. After mechanical clarification, the raw extracts were applied directly to the RP column. Alternatively, the extracts were lyophilized and subjected to size-exclusion chromatography on Sephadex G-50 in 3 M acetic acid. Two fractions with mol. wt. greater than 6000 dalton (Peak I) or with mol. wt. less than or equal to 6000 dalton (Peak II) were obtained. The Sephadex G-50 size-exclusion chromatography and the RP-high-performance liquid chromatographic (HPLC) analyses of the crude extracts from a normal pancreas clearly demonstrated the weight distribution and differences between the exocrine pancreas (containing primarily the major digestive enzymes) and the endocrine pancreas (containing insulin, glucagon, etc.). RP-HPLC analyses of crude extracts from various normal pancreatic glands resulted in very similar UV profiles, whereas those from a number of individual diabetic glands differed. Chromatograms of acetic acid extracts from normal pancreata were similar when analysed before or after lyophilization, whereas lyophilization of acetic acid extracts of diabetic glands resulted in severely obscured chromatograms. RP-HPLC analyses clearly demonstrated several differences between the diabetic and the normal pancreas. In the crude extracts, the extractable proteins from the diabetic pancreas were shifted towards lower molecular weight and/or hydrophobicity. Further, a peak co-eluting with authentic, human insulin could be demonstrated in the raw extract and in the peak II material from the normal pancreas, whereas virtually no mass signal was seen in the UV-profiles of similar materials from the diabetic gland. This finding was further verified by insulin radioimmunoassay (RIA) performed on the isolated fractions after RP-HPLC of a crude extract from a normal and a diabetic pancreas. The insulin content in the diabetic pancreas was found to be ca. 1% of that in the normal pancreas. When authentic glucagon was added to crude extracts from a diabetic pancreas, a single component was found after immediate analysis, but after several hours at room temperature the glucagon was found to be degraded. Added insulin was stable under these conditions. Similar RP analyses were performed on a silica C4 column eluted with an acetonitrile gradient in trifluoroacetic acid.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Reversed-phase high-performance liquid chromatographic characterization of acetic acid extracts of the normal and the diabetic human pancreas. 205 Jul 80

The relation of urea synthesis rate to blood alanine concentration was assessed in seven healthy controls and in 18 patients with insulin-dependent diabetes mellitus (HbAlc = 8.4 +/- 1.0% (mean +/- SD)). Following an overnight fast alanine was infused at 2 mmol h-1 kg-1 body weight. The hourly rate of urea synthesis was determined as the urinary excretion of urea corrected for accumulation of urea in total body water and intestinal hydrolysis. The functional hepatic nitrogen clearance, i.e. the relation of urea synthesis rate to blood alanine concentration, was calculated as the slope of linear regression of urea synthesis rates on blood alanine concentrations. Fasting glucagon concentrations were 85 +/- 26 ng l-1 in controls and 161 +/- 35 ng l-1 (P less than 0.01) in patients. The functional hepatic nitrogen clearances were 21.8 +/- 4.4 l h-1 in controls and 44.7 +/- 12.4 l h-1 (P less than 0.001) in patients. By multiple step-wise linear regression analysis the functional hepatic nitrogen clearance was found to correlate independently to fasting glucagon concentration, duration of diabetes, change in blood glucose and insulin following alanine infusion (r2 = 0.74). In a simple linear regression analysis the functional hepatic nitrogen clearance correlated strongly to fasting glucagon concentration (r2 = 0.54). In conclusion the kinetics of urea synthesis in insulin-dependent diabetes is changed in favour of increased conversion of alanine-N to urea-N at any blood amino acid concentration. The increased FHNC correlates strongly with hyperglucagonaemia.
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PMID:Increased hepatic efficacy of urea synthesis from alanine in insulin-dependent diabetes mellitus. 210 34

Recent results have demonstrated altered corticotropin-releasing factor (CRF)-41 content of the neurointermediate lobe (NIL) of the pituitary gland in response to various manipulations including osmotic stimulation. This study was undertaken to determine whether changes in CRF-41 content of the NIL are accompanied by changes in intensity of CRF-41-like immunoreactivity (CRF-41-LI) of neurosecretory neurones of the hypothalamus in response to osmotic stimulation. Wistar rats of both sexes given either tap water ad libitum, 2% NaCl solution, or access to tap water was limited to 20 min daily, for 7 days. Subsets of rats from each group were adrenalectomized (ADX) or treated with dexamethasone (DEX). Thirty-six hour before perfusion with fixative consisting of buffered formaldehyde and picric acid, animals received 75 micrograms colchicine i.c.v. Forty micrometer thick vibratome sections were stained for CRF-LI, arginine vasopressin (AVP-LI) and oxytocin (OXY-LI) using the avidin-biotin-peroxidase complex method. In response to both types of osmotic stimulation magnocellular neurones of the paraventricular (PVN) and supraoptic nuclei (SON) showed increased CRF-LI, AVP-LI and OXY-LI, while CRF-LI of parvocellular perikarya of the PVN decreased. The enhanced CRF-LI seemed to appear in a subset of magnocellular neurones with OXY-LI but not AVP-LI. Increased staining intensities were also observed in magnocellular neurones in ADX rats challenged osmotically. In contrast, systemic DEX administration, as well as implantation of DEX in the area on the SON, sharply attenuated CRF-LI but not AVP-LI or OXY-LI of magnocellular neurones in osmotically stimulated rats.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oxytocinergic neurons in rat hypothalamus. Dexamethasone-reversible increase in their corticotropin-releasing factor-41-like immunoreactivity in response to osmotic stimulation. 211 29

Six severely malnourished patients with chronic obstructive pulmonary disease were maintained for 3 days with infusions of 5% dextrose in water followed by 12 days of eucaloric total parenteral nutrition. On days 8 through 11, they received 30 micrograms/d of growth hormone and twice this amount on days 11 through 15. Growth hormone had no significant effects on the plasma concentration of glucose, cortisol, or glucagon but caused a 50% increase in insulin and a 250% increase in somatomedin C concentrations. A positive nitrogen balance of 2 g/d due to growth hormone was probably mediated by insulin. Growth hormone-induced increases in energy expenditure and fat oxidation and decrease in glucose oxidation cannot be accounted for by insulin. The ability of growth hormone to improve nitrogen balance may be particularly important for malnourished patients with chronic obstructive pulmonary disease who, because of their pulmonary insufficiency, are intolerant of excess nutrients.
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PMID:Growth hormone and pulmonary disease. Metabolic effects in patients receiving parenteral nutrition. 211 5

Using a within-subjects design, we gave over-weight and normal-weight subjects a 500-mL drink of fructose, glucose, or aspartame diluted in lemon-flavored water or plain water in a randomized fashion at about weekly intervals. Food intake was assessed at a buffet lunch that began 38 min after the preload was completed. Blood was drawn throughout and assayed for concentrations of glucose, insulin, glucagon, and free fatty acid. When subjects drank the fructose preload, they subsequently ate fewer overall calories and fewer grams of fat than when they drank any of the other preloads. The aspartame load did not stimulate intake beyond the plain-water control. The effects of the oxidation of fructose as a possible mechanism for the reduction in food intake is discussed. The effects of insulin in stimulating intake are also discussed.
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PMID:Comparative effects of fructose, aspartame, glucose, and water preloads on calorie and macronutrient intake. 217 91

This study was undertaken to determine the effects of ingesting 5.0 (CHO-5), 6.0 (CHO-6), and 7.5 g/100 ml (CHO-7.5) carbohydrate (CHO) solutions on blood glucose and counterregulatory hormonal responses during prolonged intermittent exercise. Eight well-trained cyclists performed four trials consisting of seven 12-min cycling bouts at 70% of VO2max with 3 min rest between each ride. A final 12 min ride was an all-out self-paced performance ride. During the rest interval the subjects ingested either a water placebo (WP) or one of the CHO solutions at a rate of 8.5 mg/kg/h (approx. 150 ml). Blood samples were taken at 0, 25, 55, 85, and 115 min of exercise and were assayed for glucose, glucagon (GG), cortisol (CT), insulin (IN), epinephrine (EP), and norepinephrine (NE). Blood glucose levels were significantly lower in the WP trial compared to the CHO trials at 25 (4.6 +/- 0.2 vs 5.7 +/- 0.5 mmol/l) and 55 min (4.4 +/- 0.3 vs 5.0 +/- 0.8 mmol/l). At 85 min blood glucose was significantly lower in the WP compared to the CHO-6 and CHO-7.5 trials. GG and IN levels were not significantly different between trials; however, the GG:IN molar ratio was significantly higher in the WP than in the CHO-7.5 trial. CT was significantly elevated in the WP trial compared to the CHO-7.5 trial. EP and NE levels were not affected by CHO ingestion. These data suggest that CHO feedings prevent the typical hormonal responses which are responsible for hepatic glucose release, thus eliciting a possible hepatic glycogen sparing.
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PMID:Influence of carbohydrate ingestion on counterregulatory hormones during prolonged exercise. 218 Aug 31


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