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)

Six normal subjects received 10 g of alanine both orally and as a 60-min intravenous infusion. In both studies blood samples for hormones and substrates were obtained every thirty minutes for 2 1/2 hour. Significant increases in whole blood levels of threonine, serine, glutamine, proline, glycine, and alpha-amino-n-butyric acid were found, which were mainly due to increases of these amino acids in the plasma compartment. In contrast, whole blood levels of leucine, valine, and isoleucine declined, mainly due to increases in the cell compartment. Plasma glucagon levels increased in both studies while insulin levels rose significantly only during the oral study. Plasma free fatty acids and blood glycerol levels declined while lactate and pyruvate increased. Glucose concentration did not change during both tests. These data suggest that the administration of large quantities of alanine is capable of inducing significant alterations in levels of other amino acids and substrates as well as changing hormone levels.
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PMID:Alanine-induced amino acid interrelationships. 116 33

The net hepatic metabolism of amino glycerol, lactate, and pyruvate was determined in conscious fed sheep by multiplying the venoarterial concentration differences by the hepatic blood or plasma flow. In each experiment several sets of control blood samples were taken; glucagon or insulin then was infused intraportally for 2 h during which additional samples were taken. Four types of experiments were performed: 1) glucagon infusion (150 mug/h) into normal sheep, 2) glucagon infusion (100 mug/h) into insulin-treated alloxanized sheep, 3) insulin infusion (1.17 U/h) into normal sheep, and 4) insulin plus glucose infusion (12.3 mmol/h) into normal sheep. The second group of experiments was performed to prevent reflex hyperinsulinemia, and the fourth was performed to prevent reflex hyperglucagonemia. Glucagon directly stimulated the net hepatic uptake of alanine, glycine, glutamine, arginine, asparagine, threonine, serine, and lactate. Glucagon also stimulated lipolysis in adipose tissue. Insulin, on the other hand, appeared to have a lipogenic effect on adipose tissue and to stimulate directly the uptake of valine, isoleucine, leucine, tyrosine, lysine, and alanine only at extrahepatic sites. The study showed that, in sheep, the effects of glucagon primarily are on liver, and insulin's effects primarily are on skeletal muscle and adipose tissue where it promotes protein and lipid synthesis.
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PMID:Effects of glucagon and insulin on net hepatic metabolism of glucose precursors in sheep. 120 Jan 53

The catabolism of glucose and amino acids has been studied in the normal, the fasted, and the fasted septic dog. The fasted septic dog oxidized more glucose and alanine, and had more gluconeogenesis from alanine and the five tritiated amino acids--glutamate, threonine, phenylalanine, leucine, and valine--as compared to the normal and equally fasted dog. Thus the total body protein catabolic state was characterized in biochemical terms. In contrast, following glucose infusion, the fasted septic animal responded much like the fasted animal in terms of decreased animo acid gluconeogenesis and decreased plasma concentrations of amino acids, fats and fat products, but considerably increased the oxidation of alanine. The increased alanine oxidation appeared to be primarily related to increased tissue clearance and increased plasma concentration. There was some suggestive evidence for enhanced oxidation of the tritiated amino acids including leucine and valine during glucose infusion. The protein catabolic state secondary to this sort of sepsis in dogs only on per os fluid support appears to be best characterized as a glucose catabolic state with alanine being oxidized directly. Such states are known to be ones of enhanced metabolic rate secondary to enhanced synthetic processes generally. This is probably related to enhanced sympathetic nervous system release of glucagon with insulin being normally responsive to glucose because of a normal plasma epinephrine.
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PMID:Turnover of amino acids in sepsis and starvation: Effect of glucose infusion. 125 26

Cirrhosis of the liver is typically accompanied by low plasma levels of the three branched chain amino acids (BCAA). These patients also demonstrate increased concentrations of several hormones such as insulin, glucagon and catecholamines. Catecholamines have been shown to influence the plasma levels of amino acids in healthy subjects and diabetics. In the present study, amino acid concentrations were investigated before and up to 3 hours after beta blockade (Inderal, 40-80 mg, n = 10) or fasting (n = 8) in cirrhotic patients. In the basal state the patients had low levels of all three BCAA, as compared with healthy subjects. Norepinephrine was more than 3 times as high in the patients (3.65 +/- 0.6 vs. 0.84 +/- 0.08 nmol/l, p < 0.01) while epinephrine was only slightly raised (0.43 +/- 0.1 vs. 0.25 +/- 0.06 nmol/l, NS). Significant correlations were observed between the concentrations of norepinephrine and individual as well as the sum of the three BCAA (r = 0.43-0.62, p < 0.05-0.001), while no correlation was observed between the BCAAs and epinephrine or insulin. Three hours after beta blockade the concentrations of leucine (basal: 74 +/- 6, 180 min: 89 +/- 6 mumol/l, p < 0.05) and valine (basal: 110 +/- 10, 180 min: 132 +/- 11 mumol/l, p < 0.01) had increased significantly. A similar tendency was observed for isoleucine. No changes were observed after prolonged fasting. The results suggest that catecholamines, primarily norepinephrine, might contribute to the low levels of BCAA in cirrhotics.
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PMID:Influence of beta blockade on branched chain amino acid concentrations in cirrhosis. 145 31

1. The effects of insulin, glucagon and a supply of exogenous amino acids on protein degradation have been studied in isolated perfused livers from growing chickens by measuring the rate of net valine release in the presence of cycloheximide. 2. Insulin inhibited protein degradation as did a supply of exogenous amino acids. 3. Addition of glucagon increased uric acid release from the livers but had no significant effect on protein degradation. 4. When the effects of the hormones and amino acid mixture are compared with published data for the rat it is evident that the action of glucagon differs in the two species.
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PMID:Regulation of intracellular protein degradation in the isolated perfused liver of the chicken (Gallus domesticus). 149 64

Leucine has been reported to be an important regulator of protein metabolism. We investigated the effect of intravenous infusion of L-leucine versus saline on amino acid metabolism in eight healthy human subjects. Plasma concentrations of amino acids were measured and protein turnover was estimated using L-(1-13C)lysine and L-(3,3,3,-2H3)leucine as tracers. Glucose kinetics were measured using D-(6,6-2H2)glucose as a tracer. Leucine infusion increased the plasma leucine concentration from 103 +/- 8 to 377 +/- 35 mumol/L (P less than .01). Plasma concentrations of essential amino acids, including threonine, methionine, isoleucine, valine, tyrosine, and phenylalanine were significantly decreased by leucine infusion. Leucine infusion did not change lysine flux significantly (108 +/- 4 during saline v 101 +/- 4 mumol/kg/h-1 during leucine infusion), but decreased lysine oxidation (13.2 +/- 0.9 v 10.7 +/- 1 mumol/kg/h, P less than .05) and endogenous leucine flux (from 128 +/- 4 to 113 +/- 7 mumol/kg/h, P less than .05) when plasma (2H3) ketoisocaproate (KIC) was used for calculation. During leucine infusion, the (2H3) KIC to (2H3) leucine plasma enrichment ratio increased from 0.76 +/- 0.02 to 0.88 +/- 0.01 (P less than .001), while estimation of leucine flux using plasma (2H3) leucine showed no change in endogenous leucine flux. Leucine infusion decreased hepatic glucose production and metabolic clearance of glucose, but did not change plasma concentrations of glucose, insulin, C-peptide, glucagon, epinephrine, norepinephrine, or free fatty acids. We conclude that leucine spares glucose and lysine catabolism and decreases plasma concentrations of essential amino acids.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of leucine on amino acid and glucose metabolism in humans. 164 Aug 50

To study the effect of ammonia administration on amino acids and indoleamines in cerebrospinal fluid (CSF) and on amino acids, insulin, and glucagon in plasma in humans with liver cirrhosis, we performed seven ammonia tolerance tests on six patients with stable liver cirrhosis. The grade of encephalopathy was determined by psychometric tests. Only one of the patients had pronounced encephalopathy. The other patients had no or only slight encephalopathy. The plasma concentrations of valine, leucine, isoleucine, phenylalanine, tyrosine, and methionine decreased after the ammonia load, whereas no changes were found in the plasma concentrations of glucagon and insulin. In CSF the concentrations of glutamine, aromatic amino acids, and indoleamines increased only in the patient who had pronounced encephalopathy, whereas no changes were found in the other patients. The effect of an ammonia load on the concentrations of neutral amino acids in CSF in patients with pronounced encephalopathy remains to be demonstrated.
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PMID:The effects of ammonia tolerance tests on the cerebrospinal fluid concentrations of amino acids and indoleamines in patients with liver cirrhosis. 169 97

Pituitary adenylate cyclase-activating polypeptide (PACAP), a peptide of the glucagon-secretin-vasoactive intestinal polypeptide superfamily, was isolated in pure form from the brain of the European green frog, Rana ridibunda. The primary structure of the peptide indicates that evolutionary pressure to conserve the complete amino acid sequence has been very strong. Frog PACAP comprises 38 amino acid residues and contains only 1 substitution (isoleucine for valine at position 35) compared with human/ovine/rat PACAP. In the presence of the phosphodiesterase inhibitor isobutylmethylxanthine, synthetic ovine PACAP-(1-38) produced a dose-dependent increase in the concentration of cAMP in isolated frog anterior pituitary fragments (ED50 = 2.1 +/- 0.6 x 10(-7) M; mean +/- SE; n = 6). Maximum stimulation (an approximately 8-fold increase in concentration over basal values) was produced by 10(-6) M peptide. The truncated form of PACAP [PACAP-(1-27)] also produced a dose-dependent increase in cAMP in frog anterior pituitary fragments, and the potency of the peptide (ED50 = 5.9 +/- 0.6 x 10(-8) M) was comparable to that of PACAP-(1-38). The data suggest, therefore, that the function as well as the structure of PACAP have been conserved during the evolution of amphibia to mammals.
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PMID:Primary structure of frog pituitary adenylate cyclase-activating polypeptide (PACAP) and effects of ovine PACAP on frog pituitary. 172 95

Hormonal changes and whole blood free amino acid levels and their relation to renal function were measured in 12 insulin-dependent diabetic patients after two 10-day periods with a diet consisting of 10% and 20% respectively of the energy as protein. The patients were 15-21 years old and mean duration of diabetes was 12 (5-20) years. Glomerular filtration rate, renal plasma flow, and albumin excretion rate were measured together with plasma concentrations of glucagon, growth hormone, insulin-like growth factor 1 (IGF-1), somatostatin, serum insulin and free amino acids in blood. Glomerular filtration rate was 123 +/- 3 ml/min/1.73 m2 on high protein diet and 113 +/- 3 ml/min/1.73 m2 on low protein diet (p = 0.02). Renal plasma flow was unchanged. Glucagon, IGF-1, branch chained amino acids (BCAA), tyrosine, phenylalanine, lysine, and methionine were increased after the high protein diet. Growth hormone, somatostatin, insulin, and other amino acids remained unchanged. The increase in glomerular filtration rate was significantly correlated to the increase in glucagon, isoleucine, and valine (glucagon r = 0.71, p = 0.01, isoleucine r = 0.59, p = 0.04, valine r = 0.62, p = 0.03). In a multiple regression model the increase in glomerular filtration correlated most strongly to the increase in isoleucine, followed by valine and glucagon. Together these variables explained 88% of the total variance of the change in glomerular filtration rate (r2 = 0.88, p = 0.001). Albumin excretion rate was correlated to IGF-1 (r = 0.86, p less than 0.001) on the high protein diet.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Indications that branched chain amino acids, in addition to glucagon, affect the glomerular filtration rate after a high protein diet in insulin-dependent diabetes. 180 76

Both albuminuria (UalbV) and albumin synthesis (AlbSyn) are modulated by dietary protein in nephrotic rats, but the agent(s) linking diet to altered UalbV and AlbSyn is unknown. Others have reported that branched-chain amino acids (BCAA) cause neither increased renal blood flow nor glomerular filtration rate (GFR) normally induced by dietary protein nor increased blood glucagon thought to be necessary for protein-mediated effects on renal hemodynamics. The effect of BCAA on UalbV is unknown. Because BCAA increase AlbSyn in tissue culture and after a fast, it is possible that feeding BCAA may increase AlbSyn but not UalbV in nephrosis. Nephrotic rats were fed either 8.5% casein (LP); 21% casein (NP); 8.5% casein supplemented with valine, leucine, and isoleucine to the total amount provided by a 21% casein diet (2.37%) (LBC); or 8.5% casein plus 12.5% BCAA providing a diet isonitrogenous to 21% casein (HBC). UalbV and AlbSyn were significantly greater in NP compared with LP, LBC, or HBC and were the same in the latter three groups. Glucagon was infused into nephrotic rats fed 8.5% casein either subcutaneously or intraperitoneally in quantities sufficient to increase plasma levels to over 10 times control but had no effect on UalbV. The ability of dietary protein to increase AlbSyn or UalbV is not a result of total alpha-amino nitrogen intake but is a result of the specific amino acid composition of the diet and must result entirely from the effect of one or more non-BCAA. Increased blood glucagon alone has no effect on UalbV.
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PMID:Branched-chain amino acids augment neither albuminuria nor albumin synthesis in nephrotic rats. 199 10


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