Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anoxia has been compared with ischaemia. The abrupt restoration of either oxygen of flow may accelerate cardiac damage. Anoxic stimulation of glycolysis (Pasteur effect) is inhibited during ischaemia by lactate and proton accumulation at the levels of phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. Anaerobic glycolysis provides lactate and ATP; breakdown of the latter provides protons. During partial respiration thought to occur in partial ischaemia, continued production of CO2 is a factor contributing to intracellular acidosis; mitochondrial ATP when formed by continued respiration also yields protons when ultimately broken down. The endoproducts of aerobic glycolysis (pyruvate and NADH) are transported into the mitochondria by the malate-aspartate cycle and by pyruvate dehydrogenase activity. Adenine nucleotide transferase activity normally transfers the mitochondrially-made ATP to the cytoplasm, but acyl CoA accumulates in ischaemia (or during perfusions with high circulating free fatty acids) to inhibit the transferase. The mitochondrial creatine kinase is thought to transform ATP transported outwards into creatine phosphate which can permeate the outer mitochondrial membrane. Further compartmentation of ATP may be by other creatine kinase isoenzymes or in relation to the cell membrane. The glycogenolytic-sarcoplasmic reticulum complex links a glycogen pool to the sarcoplasmic reticulum. Cyclic AMP may regulate admission of calcium to the cell during the plateau of the action potential and promote calcium uptake by the sarcoplasmic reticulum by phosphorylation of phospholamban. The latter promotes the activity of the calcium-transport ATPase. Calcium and cyclic AMP may also interact at the level of the contractile proteins where cyclic AMP phosphrylates troponin. Cyclic GMP generally has opposite effects to cyclic AMP and undergoes opposite changes in the frog cardiac cycle to those of cyclic AMP. A present it is reasonable to suppose that physiological effects of adrenaline or of cholinergic agents on the myocardium are mediated by cyclic AMP or cyclic GMP, respectively, but this hypothesis still lacks firm support. There is an association between tissue cyclic AMP and ventricular fibrillation after coronary ligation, and direct evidence for a role of cyclic AMP in promoting arrhythmias has been obtained by studies on the ventricular fibrillation threshold in the rat heart. However, there are other mechanisms, involving first the effects of substrates on the action potential duration, and secondly, the fast channel, which can also give rise to the development of malignant arrhythmias.
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PMID:Myocardial metabolism and heart disease. 3 41

Human erythrocytes from healthy male donors were fractionated with respect to in vivo age by simple centrifugation in order to characterize changes in the functional integrity of the membrane during the life-span of the cell. The three enzymes, Na/K-ATPase, glyceraldehyde-3-phosphate dehydrogenase and NADH-ferricyanide reductase, were found not to change with age, but significant age-dependent decreases were observed in the cases of acetylcholinesterase, phosphoglycerate kinase, purine nucleoside phosphorylase, adenylate kinase, Mg-ATPase and alkaline phosphatase. The possibility that these changes were attributable to mechanisms other than age-related inactivation, such as reticulocyte contamination, differential resealing and crypticity, was investigated. Only the decrease in acetylcholinesterase could be explained wholly in terms of reticulocyte contamination. A decrease in membrane integrity on ageing was observed, which accounted for approximately half the change in alkaline phosphatase and may have contributed to the other enzyme activity changes. This membrane integrity effect masked a real decrease in the highly cryptic NADH-ferricyanide reductase, this decrease being apparent only after total disaggregation of the membrane with nonionic surfactant.
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PMID:Changes in the activities of some membrane-associated enzymes during in vivo ageing of the normal human erythrocyte. 14 40

Biopsies from vastus lateralis muscle of male patients suffering from chronic ethanol abuse were studied with regard to histochemical reactions of ATPase and NADH-diaphorase; enzymatic activities of triosephosphate dehydrogenase (TPD), lactate dehydrogenase (LD), and cytochrome c oxidase (cytox); content of ATP, creatine phosphate, and glycogen; and volume fractions of fat, mitochondria, and fibrillar and extrafibrillar space. The results were compared with those from controls without known abuse of ethanol. The relative numbers of fibers were the same in two groups, but the size of the fast-twitch-glycolytic (white) fibers was diminished in the alcoholic group. The activities of TPD and LD were diminished in skeletal muscle of the alcoholics. This is most probably caused by the reduced amount of fast-twitch-glycolytic tissue, as there was a good correlation between this amount and the activity of the two enzymes. The activity of cytox was slightly lower in muscle of the alcoholics than in that of the controls. The volume fraction of mitochondria was lower in the alcoholic group than in the control group. Volume fractions of fat and fibrillar and extrafibrillar space were equal in the two groups. No significant differences were found in the amount of glycogen and ATP in the muscle of the two groups. However, the content of creatine phosphate is higher in the alcoholic group than in the control group.
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PMID:Effects of chronic ethanol abuse on structure and enzyme activities of skeletal muscle in man. 17 13

Binding of glyceraldehyde 3-phosphate to glyceraldehyde-3-phosphate dehydrogenase, the membrane protein known as Band 6, causes shifts in the 31P nuclear magnetic resonance spectrum of the substrate (Fossel, E.T. and Solomon, A.K (1977) Biochim. Biophys. Acta 464, 82--92). We have studied the resonance shifts produced by varying the sodium/potassium ratio, at constant ionic strength, in order to examine the relationship between the cation transport system and glyceraldehyde-3-phosphate dehydrogenase. Alteration of the potassium concentration at the extracellular face of the vesicle affects the conformation of glyceraldehyde-3-phosphate dehydrogenase at the cytoplasmic face, thus showing that a conformation changed induced by a change in extracellular potassium can be transmitted across the membrane. Alterations of the sodium concentration at the cytoplasmic face also affect the enzyme conformation, whereas sodium changes at the extracellular face are without effect. In contrast, there is no sidedness difference in the effect of potassium concentrations. The half-values for these effects are like those for activation of the red cell (Na4 + K+)-ATPase. We have also produced ionic concentration gradients across the vesicle similar to those Glynn and Lew (1970) J. Physiol. London 207, 393--402) found to be effective in running the cation pump backwards to produce adenosine triphosphate in the human red cell. The sodium/potassium concentration dependence of this process in red cells is mimicked by 31P resonance shifts in the (glyceraldehyde 3-phosphate/glyceraldehyde-3-phosphate dehydrogenase/inside out vesicle) system. These experiments provide strong support for the existence of a functional linkage between the membrane (Na+ + K+)-ATPase and the glyceraldehyde-3-phosphate dehydrogenase at the cytoplasmic face.
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PMID:Effect of the sodium/potassium ratio on glyceraldehyde 3-phosphate dehydrogenase interaction with red cell vesicles. 45 84

Human erythrocyte ghosts were solubilized in a low ionic strength medium containing 1% Triton X-100 and subjected to electrophoresis in polyacrylamide gels containing Triton X-100. Five major bands were stained with Coomassie Blue, all except one band being heterogenous when re-electrophoresed in gels containing sodium dodecyl sulphate. It was possible to detect acetylcholinesterase, non-specific esterase, ATPase, alkaline phosphatase, 5'-nucleotidase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and aldolase activities on the Triton-containing polyacrylamide gels. Two of the enzymes, ATPase and 5'-nucleotidase, showed substantial inhibition by Triton X-100 in quantitative studies. This appears to be a useful method for studying membrane enzymes in normal and pathological red cells.
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PMID:Polyacrylamide gel electrophoresis of human erythrocyte membrane enzymes solubilized with triton X-100. 89 Sep 65

The activities of Mg(2+)-dependent and Na(+)-K(+)-stimulated ATPase in homogenates of rat retina were measured in the presence of increasing concentrations of oxidized glutathione (GSSG). The Mg(2+)-ATPase was not inhibited by GSSG at any of the concentrations tested. The Na(+)-K(+)-stimulated ATPase was not inhibited by 1 mM GSSG, but its activity was decreased by 20 and 35%, respectively, in the presence of 5 and 10 mM GSSG. Other enzymatic measurements using supernatant fractions of rat retina showed that 1-10 mM GSSG did not inhibit the activities of hexokinase, glucose-6-phosphate dehydrogenase, or glyceraldehyde-3-phosphate dehydrogenase. These results suggest that GSSG is not likely to exert significant deleterious changes on cellular processes, at least in cells and tissues in which normal glutathione (GSH) concentration is 2 mM or lower.
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PMID:Effects of oxidized glutathione on ATPase activities in rat retina. 165 10

In continuation of earlier studies on murine neoplastic liver lesions, we characterized by histochemical methods the phenotype of hepatocellular adenomas and carcinomas induced by single injections of diethylnitrosamine (1.25, 2.5, or 5.0 micrograms/g of body weight) in 15-day-old C57BL/6 x male C3H F1 mice. The hepatocellular adenomas were composed predominantly of basophilic cells but stored excessive amounts of fat and glycogen in large portions of the tumors. Irrespective of the carcinogenic dose, the adenomas showed a consistent histochemical pattern. Glycogen synthase and phosphorylase were highly active in the hepatocytes that stored glycogen. In cells poor in, or free of, this polysaccharide, these enzymes were only moderately active or even inactive. In glycogen-storing parts of the adenomas, the activity of adenylate cyclase was reduced compared with normal liver parenchyma, but in fat-storing portions it was elevated. In a few adenomas, uniform increase in adenylate cyclase activity could be encountered. The levels of ATPase, acid phosphatase, and glucose-6-phosphatase were either increased or decreased. Glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase showed an increased activity in all adenomas compared with preneoplastic foci, which in turn exhibited a higher glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase activity than the surrounding parenchyma or the liver of untreated controls. The hepatocellular carcinomas showed remarkable histochemical changes compared with adenomas. The levels of fat and glycogen and the activities of glycogen synthase, phosphorylase, and in most cases also that of glucose-6-phosphate dehydrogenase, were reduced significantly. In contrast, adenylate cyclase, glucose-6-phosphatase, glyceraldehyde-3-phosphate dehydrogenase, and also alkaline phosphatase showed a striking elevation in developing carcinomas. Similar, although more pronounced, histochemical changes were seen in the advanced hepatocellular carcinomas. These observations indicated that progression from adenomas to hepatocellular carcinomas was associated with a change in the activity of several enzymes involved in cell membrane function, glycogen metabolism, the oxidative pentose phosphate pathway, and glycolysis.
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PMID:Histochemical profile of mouse hepatocellular adenomas and carcinomas induced by a single dose of diethylnitrosamine. 184 80

Focal hepatocellular lesions, induced in our infant mouse system (15-day-old B6C3F1 mice) by a single carcinogenic dose of diethylnitrosamine (2.5 or 5.0 micrograms/g body weight), were characterized histochemically using toluidine blue, periodic acid-Schiff, glycogen phosphorylase, glycogen synthetase, glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, ATPase, gamma-glutamyl transpeptidase, and acid phosphatase. Animals were killed 5, 12, 18, and 24 weeks following diethylnitrosamine treatment. The first focal lesions were observed in mice killed at 12 weeks. All foci showed patchy cytoplasmic basophilia and a slight decrease in the glycogen content. The early foci (12 weeks) showed no change in the levels of glycogen phosphorylase and glycogen synthetase, a strong reduction of glucose-6-phosphatase, and a high increase in glucose-6-phosphate dehydrogenase. In addition, 56% of foci in males and 86% of foci in females showed a slight rise in glyceraldehyde-3-phosphate dehydrogenase, and 12% of foci in males and 17% of foci in females had a lower acid phosphatase. The level of cytoplasmic ATPase was slightly decreased in 22% of foci. By 24 weeks, a decrease in the activity of cytoplasmic ATPase was observed in 84 and 100% of foci in males and females, respectively. The increase in the membrane ATPase was observed in 65% of foci in males and 7% of foci in females. By that time, the decrease in acid phosphatase was observed in 78% of foci in males and 37% of foci in females. The gamma-glutamyl transpeptidase failed to show any increase in its activity, indicating that this enzyme was not a "marker" of the hepatocellular lesions developing under the experimental conditions. Strong decrease in glucose-6-phosphatase in association with a manifest increase in glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase activities indicated a shift from gluconeogenesis to glycolysis. Since this metabolic shift occurred concurrently with an increase in the labeling indices and focal size, it appears that these changes act in concert, representing expression of the acquired functional and replicating potential of the focal cell population.
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PMID:Histochemical characterization of focal hepatic lesions induced by single diethylnitrosamine treatment in infant mice. 285 11

In rats treated orally with a single dose of aflatoxin B1 (5 mg/kg body weight) characteristic focal and nodular liver lesions developed which differed in their fine structure, enzyme histochemical pattern and growth behaviour from other types of carcinogen-induced hepatic foci and nodules described earlier. The foci were composed of a distinct cell population which showed specific structural changes of the cytoplasm. Typically, unusually large and abundant basophilic bodies consisting of highly ordered stacks of cisternae of the rough endoplasmic reticulum (ER) were arranged in long, striped bands and stood out against an acidophilic background which was due to hypertrophy of the smooth ER. We propose the descriptive terms 'tigroid cells', and 'tigroid cell foci' for this population of altered hepatocytes. Correlative cytochemical investigations on the tigroid cell foci revealed characteristic changes in carbohydrate metabolism, such as a decrease in the activity of glycogen synthetase and glycogen phosphorylase and an increase in the activity of glucose-6-phosphate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase. The activity of glucose-6-phosphatase and ATPase was normal (or partially reduced) and that of the gamma-glutamyl-transpeptidase was always lacking. A progressive increase in the number and size of the tigroid cell foci and transitions from tigroid cell foci to neoplastic nodules with similar morphological and cytochemical features were observed during the time period of 104 weeks. The mitotic index within tigroid cell foci and nodules was approximately 100 times higher than that of the surrounding hepatic tissue or the liver parenchyma of untreated control animals. The important question whether the tigroid cell foci represent a specific pre-neoplastic or early neoplastic cell population requires further investigations.
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PMID:Tigroid cell foci and neoplastic nodules in the liver of rats treated with a single dose of aflatoxin B1. 286 15

This paper presents a study of the metabolic and contractile types of 34 samples from 30 muscles in five crossbred Pietrain-Large White pigs 6 to 7 months old. The activity of the following enzymes was measured: glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydrogenase using high (LDH-h) or low (LDH-b) pyruvate concentrations in the reaction medium, citrate synthase (CS), and myofibrillar Ca-Mg activated ATPase. Haeminic iron and ultimate pH (pHu) were measured on the same samples. The results showed a negative, rather linear relationship between GAPDH, LDH and ATPase activities on the one hand and CS and haeminic iron on the other. Rather high correlations (r = 0.7 to 0.8) were observed between metabolic and contractile criteria and pHu; the red (slow) muscles had the highest pHu.
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PMID:[Enzyme metabolic and contractile activities of 30 pig muscles. Relation with the final ph attained after death]. 293 86


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