Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.49 (glucose-6-phosphate dehydrogenase)
 7,794 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, it was observed that Cd administration had effects on metal distribution and enzyme activities and induced metallothionein in the soluble fraction of the duodenal mucosa. Wistar rats were given water containing 100 ppm of Cd ad libitum for 30 days. Cd treatment caused a significant increase in the mucosal weight and in the soluble protein. The existence of metallothionein was apparent and 40% of the soluble Cd was bound to the thionein. Most of the remaining Cd was bound to the larger proteins. The activities of isocitrate dehydrogenase (ICDH) and glucose-6-phosphate dehydrogenase (G6PDH) enzymes, localized in the soluble fraction, were significantly increased by Cd ingestion. The increase of Zn and the decrease of Mn and Mg were also observed in the soluble fraction of the duodenal mucosa.
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PMID:The effect of cadmium on soluble proteins, enzymes, and essential metals of the duodenal mucosa. 14 14

The purpose of this study was to examine the in vivo effects of acute exposure to a cadmium chloride aerosol on the activity of pulmonary enzymes and selected physiologic parameters that are altered by exposure to oxidant agents. Male rats were exposed for 1 hour to 0.5 per cent aerosol of cadmium chloride. At 1,5, and 11 days after exposure to cadmium chloride, exposed rats compared to control rats (data expressed as per cent of control values) had lung-to-body weight ratios of 192, 174, and 140 per cent; lung glucose-6-phosphate dehydrogenase activities of 90, 107, and 135 per cent; lung superoxide dismutase activities of 96, 101, and 132 per cent; tidal volumes of 62, 63, and 89 per cent; respiratory frequencies of 170, 145, and 108 per cent; and lung weight-specific static deflation volumes at 30 cm water of 30, 13, and 31 per cent. A zero-order clearance of cadmium from whole lung was observed, with a half-time of 27.4 days. Light microscopic examination of lung tissue revealed initial pulmonary edema on day 1 that progressed to interstitial pneumonitis on day 5, with some recovery by 11 days after exposure. The cadmium induced biochemical, physiologic, and pathologic alterations were similar to the responses observed in lungs of rats exposed to a wide variety of pulmonary irritants; thus, the changes observed may represent a nonspecific response to tissue injury.
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PMID:Biochemical and physiologic changes in lungs of rats exposed to a cadmium chloride aerosol. 21 68

The nematicidal compound alpha-terthienyl from roots of Tagetes species generates upon irradiation with near ultraviolet light reactive oxygen species on which the in vitro nematicidal activity depends. This system was studied by following the inhibition of glucose-6-phosphate dehydrogenase by photoactivated alpha-terthienyl and protection of the enzyme activity in the absence of oxygen and by various additions. Addition of mannitol, benzoate, superoxide dismutase or catalase did not have any effect nor did H2O2. This suggests that OH., O-.2, and H2O2 are not the reactive oxygen species involved. The enzyme was protected against photoactivated alpha-terthienyl in air-saturated solutions by singlet oxygen quenchers such as histidine, methionine, tryptophan, bovine serum albumin, and NaN3. Furthermore, inactivation of the enzyme was about 3.5 times faster in D2O than in H2O. When alpha-terthienyl in CH2Cl2 was irradiated in the presence of the olefin adamantylideneadamantane, a stable dioxetane was formed which decomposed to adamantanone when heated above its melting point. These results indicate a singlet oxygen-mediated process.
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PMID:Photoactivation of the nematicidal compound alpha-terthienyl from roots of marigolds (Tagetes species). A possible singlet oxygen role. 42 57

Exposure to drinking water containing as much as 500 ppm aluminum chloride for periods of 30, 60, and 90 days had no apparent effect on male reproductive processes. In an attempt to correlate enzyme activity with particular spermatogenic cell types, postnatal development of testicular enzymes was studied. Eight enzymes were selected: hyaluronidase (H), lactate dehydrogenase isoenzyme-X (LDH-X), dehydrogenases of sorbitol (SDH), alpha-glycerophosphate (GPDH), glucose-6-phosphate (G6PDH), malate (MDH), glyceraldehyde-3-phosphate (G3PDH), and isocitrate (ICDH). Enzyme specific activities in testicular homogenates were determined. Two types of enzyme developmental patterns were observed. One was represented by H, LDH-X, SDH, and GPDH; and the other by G6PDH, MDH, G3PDH, and ICDH. The former was characterized by a change in enzyme activities from low in newborn to high in adult while in the latter this pattern was reversed. The two complementary enzyme systems crossed each other at puberty. Prior to puberty, only spermatogonial cells are present; sperm differentiation initiated at puberty adds spermatocytes and spermatids to the testicular cell population. Male rats were exposed to borax in their diet for periods of 30 and 60 days. Concentrations of boron were 0, 500, 1000, and 2000 ppm. At the end of each experimental period, the specific activities of the selected enzymes were determined in the testis and prostate. Correlations of enzyme activity with testicular histology and androgen activities of the male accessory organs were sought. In addition, plasma FSH, LH, and testosterone levels were measured to assess pituitary-testicular interaction. Plasma and testicular boron concentrations were determined and a minimum boron concentration which induced germinal aplasia and male infertility was estimated. In both 30 and 60 day feeding studies, male rats receiving 500 ppm failed to demonstrate any significant adverse effects. In contrast, male rats receiving 100 and 2000 ppm boron displayed a significant loss of germinal elements, although most of the Leydig and Sertoli cells appeared normal. Testicular atrophy was associated with a decrease in seminiferous tubular diameter and a marked reduction of spermatocytes and spermatogenic cells. These morphologic alterations were associated with a concomitant reduction of H, SDH, and LDH-X specific activities. In contrast, the specific activities of G3PDH and MDH were significantly elevated above control. The increase in these enzyme activities can be attributed to the relative enrichment of spermatogonial cells during the loss of spermatocytes and spermiogenic cells. Boron-induced male germinal aplasia was also associated with significantly elevated plasma FSH while plasma LH and testosterone levels were not significantly altered. Plasma testosterone levels were unaltered. Male fertility studies demonstrated that at the 500 ppm boron level, fertility was unaffected. However, at 1000 and 2000 ppm boron, male fertility was significantly reduced. Most effects were reversible within 5 weeks. However, the male group receiving 2000 ppm boron for 60 days remained sterile. There was no dose-related decrease in litter size or fetal death in utero. Therefore, the boron-induced infertility was apparently not due to a dominant lethal effect but rather to germinal aplasia. Boron appears toxic to spermatogenic cells at testicular concentrations of 6-8 ppm.
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PMID:Assessment of environmental factors affecting male fertility. 44 58

A method is described for the measurement of enzyme activity under xeric conditions. The reaction mixtures had water contents ranging between 0.1 and 0.6g/g of reaction mixture. For glucose 6-phosphate dehydrogenase, hexokinase and fumarase, enzyme activity became detectable (about 0.05% of the fully hydrated rate) when the water content was about 0.2g/g of reaction mixture, and for phosphoglucose isomerase, around 0.15g/g of reaction mixture. With the water content raised to 0.3g/g of reaction mixture the reaction rates were only increased to 0.1-3% of the fully hydrated rate. When the combined rates for phosphoglucose isomerase and glucose 6-phosphate dehydrogenase were measured, reasonable agreement was found between the experimental data and those calculated from the individual experimentally determined rates on the assumption that diffusion was not further limiting. A method was devised for measuring the diffusion coefficients of low-molecular-weight substances in solutions having low water contents. The diffusion coefficients of riboflavin in sorbitol solution decreased by about 100-fold when the water content of the latter was reduced from 3 to 0.25g/g of sorbitol. It is concluded that to detect enzyme activity a certain minimal amount of water is required and that above this minimum the rate is still restricted by diffusion limitation. The relevance of the results to the physical state of water in reaction mixtures and to metabolism in seeds and spores in xeric conditions is discussed.
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PMID:The effect of restricted hydration on the rate of reaction of glucose 6-phosphate dehydrogenase, phosphoglucose isomerase, hexokinase and fumarase. 47 53

To determine the effect of chronic alcohol ingestion, rats were given 15 or 25% v/v of alcohol in water for a period of 6 months. The activities of some key enzymes involved in the metabolism of glucose, mitochondrial respiratory rates, and efficiency of oxidative phosphorylation were studied in the hearts of alcohol-treated and untreated rats. In the group receiving 15% alcohol, glucose-6-phosphate dehydrogenase (G-6-PDH) was elevated. In rats given 25% alcohol, activities of G-6-PDH, aldolase, and glyceraldehyde phosphate dehydrogenase were elevated but isocitrate dehydrogenase was reduced. Mitochondrial respiratory rates and the efficiency of phosphorylation were depressed in rats given 25% of alcohol. Except for mitochondrial oxidation of pyruvate and alpha-ketoglutarate, all biochemical parameters studied were within normal limits a month after alcohol was discontinued.
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PMID:The effect of chronic ethanol ingestion on myocardial glucose and energy metabolism. 56 91

Histochemical localization of delta5-3beta-hydroxysteroid dehydrogenase (delta5-3beta-HSDH), 17beta-hydroxysteroid dehydrogenase (17beta-HSDH), 11beta-hydroxysteroid dehydrogenase (11beta-HSDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) have been studied in the kidney of white-breasted water hen, Amaurornis phoenicurus chinensis. All these enzyme activities occurred in the proximal and distal convoluted and collecting tubules, however, the intensity of these enzyme activities was more in the proximal convoluted tubules. It is suggested that these enzymes might have a role in converting certain hydroxysteroids to ketosteroids during steroid excretion.
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PMID:Hydroxysteroid dehydrogenases in the kidney of white-breasted water hen, Amaurornis phoenicurus chinensis (Boddaert). 81 73

Setaria cervi, the filarial parasite inhabiting the Indian water buffalo (Bubalus bubalis Linn.) contained almost all the enzymes involved in glycogen degradation. Significant activities of glycogen phosphorylase, glucokinase, phosphoglucomutase, phosphoglucose isomerase, phosphofructokinase, FDP-aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate hydratase, pyruvate kinase, lactate dehydrogenase glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were detected in cell-free extracts of whole worms. The presence of PEP-carboxykinase, malate dehydrogenase, fumarase and fumarate reductase revealed the functioning of the PEP-succinate pathway in addition to phosphorylating glycolysis and pentose phosphate pathway in the parasite. Excepting fumarate reductase all other enzymes were localized in the particulate-free cytosol fraction, although small amounts of glycogen phosphorylase, aldolase and lactate dehydrogenase were also detected in the mitochondrial fraction.
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PMID:Setaria cervi: enzymes of glycolysis and PEP-succinate pathway. 86 May 72

The purpose of this study was to investigate the hypothesis that paraquat pulmonary toxicity results from cyclic reduction-oxidation of paraquat with sequential generation of superoxide radicals and singlet oxygen and initiation of lipid peroxidation. In vitro mouse lung microsomes catalyzed an NADPH-dependent, single-electron reduction of paraquat. Incubation of paraquat with NADPH, NADPH-cytochrome c reductase, and purified microsomal lipid increased malondialdehyde production is a concentration dependent manner. Addition of either superoxide dismutase or a single oxygen trapping agent 1,3-dipheylisobenzo furan inhibited paraquat stimulated lipid peroxidation. In vivo, pretreatment of mice with phenobarbital decreased paraquat toxicity, possibly by competing for electrons which might otherwise reduce paraquat. In contrast, paraquat toxicity in mice was increased by exposure to 100% oxygen and by deficiencies of the antioxidants selenium, vitamin E, or reduced glutahione (GSH). Paraquat, given IP to mice, at 30 mg/kg, decreased concentrations of the water-soluble antioxidant GSH in liver and lipid soluble antioxidants in lung. Oxygen-tolerant rats, which hae increased activities of pulmonary enzymes which combat lipid peroxidation, were also tolerant to lethal doses of paraquat as indicated by an increased paraquat LT50. Furthermore, rats chronically exposed to 100 ppm paraquat in the water had elevated pulmonary activities of glucose-6-phosphate dehydrogenase and GSH reductase. These results were consistent with the hypothesis that lipid peroxidation is involved in the toxicity of paraquat.
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PMID:Paraquat toxicity: proposed mechanism of action involving lipid peroxidation. 101 17

The effect of cooling rate and subsequent warming rate on survival of lactose-limited Escherichia coli was investigated. As previously reported, in the slow cooling rate range, a peak of survival was noted at 8 degrees C/min with survival decreasing as the cooling rate was increased or decreased from this value. Minimal survival was noted at 100 degrees C/min; increasing the cooling rate above 100 degrees C/min increased survival. At cooling rates greater than 200 degrees C/min, the survival became dependent on subsequent warming rates. Permeability damage, as measured by release of UV-absorbing material, potassium and beta-galactosidase, and increased accessibility of glucose-6-phosphate dehydrogenase to its substrates, was dependent on the cooling rate when cells were frozen in either water or saline. For cooling rates less than about 8 degrees C/min, there was minimal permeability damage to cells frozen in water. However, at rates greater than this value, damage and viability were related; the lower the viability the more the damage to the permeability barrier. The relationship was strengthened by the observations that protectants which increased survival reduced damage as well and that at ultrarapid cooling rates where survivals were dependent on warming rates, the extent, of damage was likewise dependent on the warming rate. Saline frozen cells were damaged by freezing and thawing more than comparable water-frozen cells over the whole cooling rate range. At cooling rates less than 8 degrees C/min, frozen in water, permeability damage of cells frozen in saline increased as the cooling rate decreased. As the cooling rate was increased from 8 degrees C/min, the damage increased as viability decreased. The relevance of these findings to the two-factor hypothesis of cell death is discussed.
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PMID:The survival of Escherichia coli from freeze-thaw damage: permeability barrier damage and viability. 110 19


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