Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.28 (lactic acid dehydrogenase)
 476 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biochemical studies were performed on blood and lung tissue of squirrel monkeys (Saimiri sciureus) following acute exposure to 0.75 ppm ozone (O3) for 4 h/d for 4 consecutive days. One group of animals was sacrificed at the end of the last exposure day and another group was sacrificed 4 d later after the last exposure. Evidence was sought for oxidation-induced changes known to occur in rodents when high levels of O3 are inhaled. A significant increase in red blood cell membrane fragility was observed, as well as significant decreases in red blood cell glutathione and erythrocyte acetylcholinesterase; however, the red blood cell enzymes, lactic acid dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G6PDH) were not changed significantly. Lung tissue analysis showed that lipid peroxidation was markedly increased and tissue vitamin E levels were significantly decreased. The tissue enzymes G6PDH, glutathione reductase, and LDH significantly increased in activity. No significant changes were seen in either superoxide dismutase or malic acid dehydrogenase. The results of this experiment indicate that O3, or reaction products resulting from O3-tissue interaction in the lung, pass the air-blood barrier and are capable of producing biochemical changes in blood as well as in lung tissue.
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PMID:Biochemical response of squirrel monkeys to ozone. 10 43

To determine whether vitamin E (dl-alpha-tocopherol) supplementation of the diet provides protection from inhaled oxidants such as ozone (O3) in community air pollution, its effects were studied in healthy adult volunteers, Experimental groups received 800 or 1600 IU of vitamin E for 9 wk or more; control groups received placebos. Double-blind conditions were maintained throughout the study. Biochemical parameters studied included red blood cell fragility; hematocrit and hemoglobin values; red cell glutathione concentration; and the enzymes acetylcholinesterase, glucose-6-phosphate dehydrogenase, and lactic acid dehydrogenase. No significant differences between the responses of the supplemented and placebo groups to a controlled O3 exposure (0.5 ppm for 2 h) were found for any of these parameters. The results indicate that vitamin E supplementation in humans, at the levels employed in this experiment, gives no added protection against blood biochemical effects of O3 in intermittently exercising subjects under exposure conditoins simulating summer ambient air pollution episodes.
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PMID:Human biochemical response to ozone and vitamin E. 52 40

The activities of twelve enzymes were measured in crude extracts from cells of Escherichia coli K-10 grown aerobically or anaerobically in a defined medium in the presence or absence of nitrate. The activities of isocitrate dehydrogenase, aconitate hydratase, 2-oxoglutarate dehydrogenase, malate dehydrogenase, malic enzyme, and D-lactate dehydrogenase (NAD+-independent) were found to be higher in cells grown in nitrate respiration than in those in fermentation, but lower than in those in respiration. This finding may explain the incomplete oxidation in nitrate respiration and, on the other hand, suggests the operation of the tricarboxylic acid even under these conditions. The activities of succinate dehydrogenase and alcohol dehydrogenase in relation to the formation of fermentation product were as high in cells grown in fermentation as in those in respiration and were low in those in nitrate respiration. However, that ratio of the activities in the latter case to the activities in respiration was the same as the ratio for most enzymes in the tricarboxylic acid cycle. The level of lactate dehydrogenase (NAD+-dependent) was not affected by nitrate respiration but its activity in the extract was inhibited by nitrate and nitrite. The absence of lactate in the anaerobic culture with nitrate may be due to this inhibition as well as NADH oxidation by nitrate. Levels of glucose-6-phosphate dehydrogenase and glutamate dehydrogenase were not altered by the growth conditions and that of pyruvate dehydrogenase was low only in cells grown in fermentation.
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PMID:Effect of nitrate reduction on the enzyme levels in carbon metabolism in Escherichia coli. 77 52

Cell-free extracts of Clostridium perfringens were found to contain all the enzymes of the Embden-Meyerhof pathway of glycolysis in addition to lactic acid dehydrogenase and the pyruvate-clastic system. Neither glucose-6-phosphate dehydrogenase nor 6-phosphogluconate dehydrogenase activities could be demonstrated, suggesting the absence of the conventional hexose-monophosphate pathway in this organism.
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PMID:Glucose degradation in Clostridium perfringens type A. 431 71

Wine strains belonging to the genus Leuconostoc were classified as Leuconostoc oenos by Garvie in 1967, and this name was confirmed on the Approved Lists of Bacterial Names in 1980. L. oenos is distinguished from other Leuconostoc spp. by its growth in acidic media, by its requirement for a growth factor in tomato juice, and by a number of carbohydrate fermentation characteristics. In addition, the results of a total soluble cell protein analysis, an electrophoretic analysis of NAD-dependent D-(-)-lactate dehydrogenase, 6-phosphogluconate dehydrogenase, and alcohol dehydrogenase, and an analysis of cross-reactivity with anti-glucose-6-phosphate dehydrogenase and anti-NAD-dependent D-(-)-lactate dehydrogenase performed with other Leuconostoc spp. clearly indicated that L. oenos should be distinguished from the other Leuconostoc species. Phylogenetic studies, in particular 16S and 23S rRNA sequencing studies, have revealed that L. oenos represents a distinct subline that is separate from other Leuconostoc spp. and lactic acid bacteria. In view of the phenotypic and phylogenetic distinctiveness of L. oenos, we propose that this species should be assigned to a new genus as Oenococcus oeni [corrig.] gen. nov., comb. nov. The type strain of O. oeni is NCDO 1674 (= ATCC 23179).
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PMID:Proposal to reclassify Leuconostoc oenos as Oenococcus oeni [corrig.] gen. nov., comb. nov.. 753 74

We examined the effect of exposure to 5500 m on three closely related metabolic pathways: anaerobic glycolysis, the pentose phosphate shunt (PPS), and fatty acid metabolism. Rats were exposed to simulated altitude of 5500 m for up to 3 months. The maximal rate of lactate production in tissue homogenates, tissue lactic acid dehydrogenase and blood lactate levels were measured to evaluate the capacity for anaerobic glycolysis. The uptake of 14C-1-palmitate, oxidation of 14C-1-palmitate to 14CO2, incorporation of 14C-1-palmitate into tissue lipids, plasma and tissue free fatty acids (FFA) levels and total lipid contents were measured to assess the magnitude of lipid metabolism. Activities of glucose-6-phosphate dehydrogenase (G-6-PD) and 6-phophogluconate dehydrogenase (6-PGD) in the PPS pathway were measured to assess the capacity to generate reducing power. Acute and chronic hypoxia did not affect most of the measurements of anaerobic glycolysis, but depressed lactate production in liver and kidney. Chronic hypoxia enhanced all aspects of lipid metabolism in liver and enhanced the uptake and oxidation to CO2 of palmitate in skeletal muscle. Chronic hypoxia did not alter the activity of the G-6-PD in any tissue studied, but the activity of 6-PGD was depressed in heart, kidney, thymus and adrenal gland. The lack of major changes in the capacities of anaerobic glycolytic pathways and the activities of the PPS dehydrogenases is consistent with the maintenance of normal aerobic metabolism in rats at 5500 m. We found no evidence that anaerobic metabolic processes were upregulated to sustain energy consumption during chronic hypoxia. On the other hand, enhanced fatty acid metabolism may spare carbohydrate for metabolic fuel under conditions of extreme hypoxic limitation.
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PMID:Effects of exposure to a simulated altitude of 5500 m on energy metabolic pathways in rats. 1523 76

The ability of reduced nicotinamide adenine dinucleotide (NADH), generated through the activity of lactic acid dehydrogenase, to support the reduction of endogenous oxidized glutathione in intact human erythrocytes and in hemolysates was investigated. Rapid initial oxidation of endogenous reduced glutathione was effected with methyl phenylazoformate. Freshly obtained normal erythrocytes and erythrocytes deficient in glucose-6-phosphate dehydrogenase activity were unable to regenerate reduced glutathione upon incubation with lactate. Only normal erythrocytes were capable of reducing oxidized glutathione after preincubation with glucose, inosine, or a medium which promoted the synthesis of increased amounts of intracellular NAD. This regeneration of reduced glutathione could be explained by the generation of reduced nicotinamide adenine dinucleotide phosphate through the metabolism of accumulated phosphorylated intermediates of glycolysis. Hemolysates prepared from both normal erythrocytes and from erythrocytes deficient in glucose-6-phosphate dehydrogenase activity were able to reduce oxidized glutathione in the presence of added lactate and NAD. The results obtained indicated either an inability of the intact erythrocyte to utilize the NAD at the concentrations attained or an altered behavior of the system for the regeneration of reduced glutathione after lysis of the cell.
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PMID:Reduced nicotinamide adenine dinucleotide and the reduction of oxidized glutathione in human erythrocytes. 1669 46