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 lowering the liver pyridoxal phosphate (PLP) concentration by vitamin B-6 deficiency on the stability of several rat liver enzymes were examined. Three PLP-dependent enzymes (serine dehydratase, ornithine-delta-aminotransferase, and tyrosine aminotransferase) and two non-PLP-dependent enzymes (glucose-6-phosphate dehydrogenase and phosphoenolpyruvate carboxykinase) were induced in vitamin B-6 deficient and control rats by feeding them high-protein diets or by injecting them with glucagon or dexamethasone. The decline of each activity was followed after withdrawal of the inducer. Serine dehydratase activity declined more rapidly in vitamin B-6 deficient than in control liver; however, ornithine aminotransferase and tyrosine aminotransferase activities were equally stable in deficient and control liver. Ornithine aminotransferase was predominantly in holoenzyme form in both control and deficient rats, whereas tyrosine aminotransferase was predominantly in apoenzyme form in both groups. The proportion of serine dehydratase in apoenzyme was less stable than the holoenzyme. Activity changes of glucose-6-phosphate dehydrogenase and phosphoenolpyruvate carboxykinase in control and vitamin B-6 deficient rats were similar. The results suggest that differences in the stability of PLP-dependent enzymes in vitamin B-6 deficient rats depend upon differences in the proportions of these enzymes existing as holo- and apoenzyme.
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PMID:Stability of some pyridoxal phosphate-dependent enzymes in vitamin B-6 deficient rats. 0 99

Glucagon, epinephrine and cyclic adenosine 3',5'-monophosphate (cyclic AMP) prevented the induction of liver glucose-6-phosphate dehydrogenase (G6PD) by refeeding a glucose-casein mixture to starved rats. The prevention by these agents occurred without any change in the amount of diet consumed. When the injection of cyclic AMP and the refeeding of glucose-casein diet were initiated simultaneously, there was an inhibiton of G6PD induction depending upon the dose and frequency of cyclic AMP administration during the period of refeeding, while when cyclic AMP was given later than 12 h of the refeeding, the lag period for induction of this enzyme, there was no preventive effect. A glucose prefeeding was also found to counteract the inhibitory effect of cyclic AMP on G6PD induction by the subsequent glucose-casein refeeding. The present data together with the elimination of actinomycin D effect by the glucose prefeeding suggest that the inhibitory effect of cyclic AMP on the induction of G6PD dehydrogenase is exerted at the level of transcription.
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PMID:Prevention of dietary induction of rat liver glucose-6-phosphate dehydrogenase by cyclic adenosine 3'.5'-monophosphate and its elimination by glucose prefeeding. 18 84

Glucagon effectively prevented the increase in glucose-6-phosphate dehodrogenase activity of rat liver following the administration of a glucose-casein mixture without altering the amount of the diet consumed. However, the increase of the enzyme level in carbon tetrachloride-injured rat liver was virtually insensitive to glucagon. The results obtained gave further evidence for the difference between these two induction mechanisms of glucose-6-phosphate dehydrogenase.
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PMID:Differential effects of glucagon on induction of rat liver glucose-6-phosphate dehydrogenase by liver injury and dietary change. 127 34

Fetal hepatocytes cultured for 64 h in the presence of glucagon and dexamethasone maintain a quiescent state, showing a low expression of glucose-6-phosphate dehydrogenase (G6PD) and a high induction of phosphoenolpyruvate carboxykinase (PEPCK). Under these culture conditions, the presence of EGF produced hepatocyte proliferation, with a concomitant increase of DNA synthesis, DNA content, and G6PD expression, meanwhile the expression of PEPCK was drastically reduced. The presence of forskolin plus IBMX nearly suppressed the increase in DNA synthesis and G6PD expression induced by EGF, showing a very high expression of PEPCK. Accordingly, it is possible to establish an inverse relation between G6PD, highly expressed in proliferating fetal hepatocytes, and PEPCK expression, highly expressed in quiescent fetal hepatocytes under specific hormonal stimulation.
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PMID:Phosphoenolpyruvate carboxykinase and glucose-6-phosphate dehydrogenase expression in fetal hepatocyte primary cultures under proliferative conditions. 131 82

Rainbow trout, Oncorhynchus mykiss, were used to evaluate the effects of carbohydrate loading on plasma levels of pancreatic hormones and associated changes in metabolic indexes in a carnivorous fish. Glucose (3,000 mg/dl, 10 microliters/g body wt) was injected intraperitoneally into fish (mean wt 54 +/- 5 g) that were killed 0.5-24 h after administration. Glucose injection resulted in hyperglycemia with maximum glucose levels of 306 +/- 13 mg/dl observed 60 min after injection. Glucose administration also resulted in hyperlipidemia. Plasma fatty acids increased twofold in glucose-injected animals. Alterations in plasma metabolites reflected changes in energy stores. Although total lipid concentration was unaffected by glucose injection, lipolytic enzyme activity in the liver was enhanced. Biosynthetic capacity, as indicated by NADPH production from glucose-6-phosphate dehydrogenase, was decreased by glucose injection. Liver glycogen content was reduced in glucose-injected animals 1 h after injection. Glucose injection was attended by increases in the plasma levels of gene II somatostatin-25 (predominant form of pancreatic somatostatin in salmonids) and of glucagon. Insulin levels were initially suppressed after glucose injection. These results indicate that metabolic adjustments caused by glucose administration can be related to the regulatory action of pancreatic hormones. Furthermore, these results suggest that the somatostatin-secreting cells of the trout are sensitive to glucose and that somatostatin-suppressed insulin secretion contributes to the glucose intolerance of trout.
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PMID:Insulin suppression is associated with hypersomatostatinemia and hyperglucagonemia in glucose-injected rainbow trout. 167 8

Administration of dehydroepiandrosterone (DHEA) to rats results in alterations in liver and serum factors. This study was undertaken to determine the earliest metabolic change(s) associated with DHEA treatment. Serum cholesterol, triacylglycerol, glucose, insulin, glucagon, thyroid hormones and hepatic glucose-6-phosphate dehydrogenase activity were, in general, unaltered in obese Zucker rats after 7 d and 24, 12 and 3 h of DHEA treatment. Malic enzyme, long-chain fatty acyl-coenzyme A hydrolase and catalase activities and peroxisomal beta-oxidation rates were elevated after 7 d and 24 h in DHEA treatment, but not after 12 h. Mitochondrial beta-oxidation was not altered. Hepatic mitochondrial state 3 respiration per g liver with glutamate-malate was elevated after 7 d and 24, 12 and 3 h in DHEA-treated rats and was elevated per mg protein except after 7 d. Succinate-supported state 3 respiration per g liver was also elevated after 7 d and 24 and 12 h of DHEA treatment. Mitochondria from rats treated for 7 d had lower levels of cardiolipin and phosphatidylethanolamine and an increase in phosphatidylcholine. Changes in fatty acid composition of these phospholipids occurred after 7 d and 24 h of DHEA treatment. In an additional study, rats were treated with DHEA or DHEA plus ethidium bromide for 3 d. Ethidium bromide inhibited the increase in mitochondrial protein and respiration associated with DHEA treatment. These findings indicate that mitochondrial respiration is the earliest factor affected by DHEA and may be associated with protein synthesis.
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PMID:Short-term effects of dehydroepiandrosterone treatment in rats on mitochondrial respiration. 182 28

Juvenile coho salmon (Oncorhynchus kisutch) were placed on five dietary regimes: fed 1 week, fasted 1 week, fed 3 weeks, fasted 3 weeks, and fasted 1 week/refed 2 weeks. Plasma levels of glucose, fatty acids, insulin, glucagon, and glucagon-like peptide (GLP) and the activities of key metabolic enzymes were determined. Plasma glucose levels in the fed control groups were 98.4 +/- 3.4 (SEM) and 104.8 +/- 4.7 mg/dl at 1 and 3 weeks, respectively. Plasma glucose in the fasted 1 week group was significantly elevated to 128.8 +/- 9.2 mg/dl. Animals fasted 3 weeks or fasted 1 week/refed 2 weeks displayed plasma glucose levels similar to those of fed animals. Fasted groups possessed significantly less liver glycogen than fed or fasted/refed groups. Plasma fatty acids were elevated only after 3 weeks of fasting (from 0.39 +/- 0.04 microEq/ml to 0.61 +/- 0.06 microEq/ml). This response was reflected in elevated liver lipase activity (from 6.02 +/- 0.44 nmol fatty acid released/hr/mg protein to 14.22 +/- 0.90 units). No significant alterations in liver lipogenesis, assessed by glucose-6-phosphate dehydrogenase activity and by 3H2O incorporation into fatty acids, were observed. Gluconeogenic flux, determined indirectly through kinetic parameters of pyruvate kinase, was enhanced in animals fasted 3 weeks and in animals recovering from a 1-week fast. Plasma insulin levels were highest in fed groups (7.7 +/- 2.3 and 5.9 +/- 1.4 ng/ml at 1 week and 3 weeks, respectively) and were significantly depressed in fasted groups. Plasma levels of glucagon and GLP were also depressed in fasted groups. These results indicate that plasma glucose levels are maintained in salmon during fasting and that fasting-induced hyperlipidemia is mediated by lipolytic enzyme activity. Insulin, glucagon, and GLP may interact with these enzyme systems to coordinate nutritional metabolism of fish.
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PMID:Effects of nutritional state on in vivo lipid and carbohydrate metabolism of coho salmon, Oncorhynchus kisutch. 205 44

The effects of the administration of insulin and glucagon on the intraacinar heterotopy of phosphoenolpyruvate carboxykinase (PEPCK) were investigated in male and female rat liver. Insulin did not noticeably influence PEPCK activity or its acinar distribution, either in males or in females. But it affected the activities of glucose-6-phosphate dehydrogenase and malic enzyme. Glucagon in supraphysiological concentrations led to an induction of PEPCK activity. Despite high glucagon concentration along the whole sinusoidal length, the inducing effect of glucagon was most pronounced in the periportal and intermediary parts of the acinus; thus indicating that there is no direct interrelationship between local glucagon concentration and PEPCK activity. In both experiments blood glucose levels were kept fairly constant.
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PMID:The heterotopic effects of insulin and glucagon on the acinar activity pattern of phosphoenolpyruvate carboxykinase in male and female rat liver. 209 Jan 60

Metabolic changes in rats fed a low protein diet were investigated during 3 weeks after weaning using lactalbumin (LP) as dietary protein source. The energy intake was higher and the weight gain lower in rats fed the low protein diet (6%, LP group) than in control rats (13% lactalbumin, C group). Low protein diet induced no changes in plasma glucose, free fatty acids, or triacylglycerol concentrations; however, plasma protein and urea concentrations were lower in LP than in C rats. Plasma free T3 was higher in LP than in C rats (+38%, day 21) and insulin progressively decreased during the experimental period (-56%, day 21) without change in glucagon. Liver glycogen and triacylglycerol concentrations (+40% and +180%, respectively, day 21), and cytosolic and mitochondrial redox states increased (+100% and +100%, day 21), and protein concentration was decreased (-15%, day 21). Pyruvate kinase (PK) and malic enzyme activities were higher in LP than in C rats throughout the experiment (+80% and +210%, respectively, day 21), and glucose-6-phosphate dehydrogenase (G6PDH) activity progressively decreased (-65%, day 21). Phosphoenolpyruvate carboxykinase (PEPCK) activity increased after 2 weeks on a LP diet (+35%, day 21) and fatty acid synthetase (FAS) activity increased only during the first week on the diet (+100%, day 7). Such hormonal and metabolic changes appeared to be associated with the development of a futile energy-wasting cycle between pyruvate and phosphoenolpyruvate.
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PMID:Metabolic changes in rats fed a low protein diet during post-weaning growth. 219 92

The effect of a long-acting somatostatin analogue on the acute renal hypertrophy following induction of experimental diabetes in the rat has been studied. The kidney weight increase occurring at 2 and 7 days after alloxan injection was significantly lower in the diabetic group receiving somatostatin. Similarly, the previously reported increase in glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) found in the kidney at 2 and 7 days of diabetes was less marked in the group receiving SMS 201-995. The fall in renal phosphoribosyl pyrophosphate associated with early diabetic renal hypertrophy (7) was also lessened by administration of SMS 201-995. No effects of the drug were found in the normal rat on the same regimen of treatment. These observations indicate involvement of glucagon and/or growth hormone in the initiation of kidney growth in diabetes.
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PMID:The effect of a somatostatin analogue (SMS 201-995, Sandostatin) on the concentration of phosphoribosyl pyrophosphate and the activity of the pentose phosphate pathway in the early renal hypertrophy of experimental diabetes in the rat. 245 25


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