Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.5.1.18 (glutathione S-transferase)
 22,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Polyclonal antisera to manganese and copper-zinc superoxide dismutases, catalase, glutathione peroxidase (GPx), and isozymes of glutathione S-transferase (liver and placental isolates, GST-L and GST-P, respectively) were used to localize these enzymes in normal rat lung by immunostaining. Light-microscopic results, using an immunoperoxidase technique, were expanded on by electron-microscopic immunogold localization. The findings were consistent with previous biochemical work. However, both GPx and GST-P were predominantly localized to extracellular connective tissue of the lung. These findings demonstrate the basal antioxidant enzyme phenotypes for parenchymal lung tissue at light- and electron-microscopic levels. Significant components of enzymatic defense to oxidant stress are heterogeneously distributed throughout rat lung tissue including both epithelial cell surfaces and the extracellular matrix.
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PMID:Immunolocalization of antioxidant enzymes and isozymes of glutathione S-transferase in normal rat lung. 128 3

Long-Evans Cinnamon (LEC) rat, an animal model of Wilson's disease, that develops a necrotizing hepatic injury with an abnormally high hepatic copper accumulation exhibits an altered expression of glutathione S-transferase (GST) subunits, that is, a low percentage of the Ya and a high percentage of the Yc subunit expression in males. The altered expression of GST subunits and the abnormal copper accumulation in liver were found to be completely correlated in male LEC mutant rat liver, suggesting that the copper toxicity caused by the anomaly of copper metabolism in LEC rat liver leads to the altered expression of GST subunits.
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PMID:Correlation between a hepatic copper accumulation and an altered expression of glutathione S-transferase Ya/Yc subunits in LEC mutant rat. 151 56

Influences of dietary selenium (Se) deficiency, physical training and an acute bout of exercise on myocardial antioxidant enzyme activity, lipid peroxidation and related biochemical properties were investigated in post-weanling male Sprague-Dawley rats. An experimental group was fed a diet containing less than 0.01 mg Se/kg and had free access to distilled water (Se-D), whereas control rats were supplemented with 0.5 mg Se/l in drinking water (Se-A). Se deficiency depleted heart mitochondrial and cytosolic Se-dependent glutathione peroxidase activity to 24 and 3%, respectively, of those in Se-A rats. Heart mitochondrial superoxide dismutase (Mn SOD) activity was 24% higher (p less than 0.05) in Se-D than in Se-A rats. Cytosolic (copper-zinc) SOD and catalase activities were not altered, whereas glutathione S-transferase activity was significantly decreased in Se-D (p less than 0.01). Myocardial antioxidant enzyme activities were not affected by either training or an acute exercise bout. Heart lipid peroxidation and activities of several enzymes in substrate metabolism were also unaffected by Se or exercise. It is concluded that rat heart has sufficient reserve of antioxidant enzyme capacity in coping with oxidative stress imposed by Se deficiency or exercise. The adaptation of Mn SOD may reveal its potential role in myocardial antioxidant defense.
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PMID:Antioxidant enzyme response to selenium deficiency in rat myocardium. 153 41

The true Michaelis constant for GSH and CDNB was 0.287 mM and 0.180 mM, respectively. Regarding the quantitative effect of Cu(II) and Cd(II) inhibition on the GST system, the I50 value for Cu(II) was 0.250 mM; in contrast, Cd(II) GST-inhibition did not reach the I50 value. When the varied substrate was GSH and CDNB was fixed at saturant concentration, the Cu(II)-inhibition was consistent with a pure competitive pattern. However a mixed pattern was found when CDNB was the varied substrate and GSSH was fixed at saturant concentration. The Cd(II) inhibition effect was consistent with an uncompetitive pattern when GSH was the varied substrate and CDNB was kept at saturant level. When CDNB changed over an extensive range of concentration, the inhibition effect shows a mixed inhibition pattern with a competitive character. In addition the inhibition constants of Cu(II) were one order of magnitude lower than those of Cd(II).
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PMID:Cu(II) and Cd(II) inhibition of rat liver glutathione S-transferase. A steady-state kinetic study. 177 28

Dietary copper deficiency was produced in Swiss albino mice and Sprague Dawley rats to compare changes in selected antioxidant enzymes. A 5-wk dietary treatment was employed, starting approximately 1 wk after birth for mice (initially via dams) and 3 wk after birth for rats. An additional confirmatory experiment was conducted with mice using the postweanling paradigm. Mouse offspring (6 wk of age) and rats (8 wk of age) maintained on a Cu-deficient treatment were compared with Cu-adequate controls. Compared with Cu-adequate animals, Cu-deficient mice and rats were anemic, had lower ceruloplasmin activities and liver copper levels, and had higher relative weights of heart and small intestine. Activity of cytochrome c oxidase (mice) and Cu,Zn-superoxide dismutase (mice and rats) was lower in all seven organs examined from Cu-deficient animals compared with Cu-adequate animals, although there were organ and species differences. Compared with Cu-adequate controls, glutathione peroxidase activity was lower in liver and plasma of Cu-deficient mice and rats. Hepatic glutathione transferase activity was markedly lower in those Cu-deficient mice started on treatment at 1 wk of age but not in those mice or rats subjected to postweanling copper deficiency.
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PMID:Changes in Cu,Zn-superoxide dismutase, cytochrome c oxidase, glutathione peroxidase and glutathione transferase activities in copper-deficient mice and rats. 184 85

In this study, acute and chronic responses of pancreatic hepatocytes induced in F-344 rats by copper depletion-repletion protocol to certain hepatocarcinogens were examined. Administration of a single dose of tannic acid (subcutaneous), aflatoxin B1 (gavage), or lasiocarpine (intraperitoneally) caused characteristic nucleolar segregation in parenchymal cells of liver as well as in pancreatic hepatocytes. Chronic dietary administration of 2-acetylaminofluorene (0.025%) for 12 to 32 weeks led to the development of glutathione S-transferase-P-positive pancreatic hepatocytes in the pancreas. In addition, oval cell proliferation was observed in close association with pancreatic hepatocytes, but not in other areas of pancreas containing residual acinar cells. Oval cells in the pancreas and in the liver that developed in rats after chronic 2-acetylaminofluorene treatment and pancreatic duct cells stained positively with rat liver oval cell marker OV-6 antibodies by immunoperoxidase. These findings indicate that pancreatic hepatocytes respond to carcinogens in a fashion similar to parenchymal cells of liver.
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PMID:Alterations of pancreatic hepatocytes in rats exposed to carcinogens. 195 28

Two groups (n = 5) of male weanling Wistar rats were housed individually and fed copper (Cu)-deficient (0.5 mg Cu/kg) diets either with or without methionine supplementation (18 g/kg) for 49 days. Plasma caeruloplasmin (EC 1.16.3.1) and erythrocyte superoxide dismutase (EC 1.15.1.1, CuSOD) activities were measured in blood. Tissue Cu levels and the activities of cytochrome c oxidase (EC 1.9.3.1, CCO) and CuSOD were measured in the heart and liver. Hepatic activities of the sulfhydryl-sensitive enzymes, creatine kinase (EC 2.7.3.2), fumarase (EC 4.2.1.2) glutathione S-transferase (EC 2.5.1.18) and lipoamide dehydrogenase (EC 1.6.4.3) were also measured. Apart from cardiac CCO activity all of the measured indices of Cu status were found to be significantly (p less than 0.05) decreased in the methionine supplemented rats. Although fumarase activity was significantly (p less than 0.05) decreased in the methionine-supplemented animals compared with controls, the activities of the other sulfhydryl-sensitive enzymes were not significantly decreased. These results suggest that some of the toxic effects of excess dietary methionine may be mediated through interference with copper metabolism rather than through the previously postulated inhibition of sulfhydryl-sensitive enzymes by metabolites of methionine.
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PMID:Excess dietary methionine decreases indices of copper status in the rat. 216 46

Free radicals are found to be involved in both initiation and promotion of multistage carcinogenesis. These highly reactive compounds can act as initiators and/or promoters, cause DNA damage, activate procarcinogens, and alter the cellular antioxidant defense system. Antioxidants, the free radical scavengers, however, are shown to be anticarcinogens. They function as the inhibitors at both initiation and promotion/transformation stage of carcinogenesis and protect cells against oxidative damage. Altered antioxidant enzymes were observed during carcinogenesis or in tumors. When compared to their appropriate normal cell counterparts, tumor cells are always low in manganese superoxide dismutase activity, usually low in copper and zinc superoxide dismutase activity and almost always low in catalase activity. Glutathione peroxidase and glutathione reductase activities are highly variable. In contrast, glutathione S-transferase 7-7 is increased in many tumor cells and in chemically induced preneoplastic rat hepatocyte nodules. Increased glucose-6-phosphate dehydrogenase activity is also found in many tumors. Comprehensive data on free radicals, antioxidant enzymes, and carcinogenesis are reviewed. The role of antioxidant enzymes in carcinogenesis is discussed.
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PMID:Free radicals, antioxidant enzymes, and carcinogenesis. 219 55

The in vitro interaction of mercury, copper (II) and cadmium with human glutathione transferase (GST) pi was studied using reduced glutathione (GSH) and 1-chloro-2,4-dinitrobenzene as substrate. Tumor specific human GST pi was isolated from the human hepatoma derived PLC/PRF/5 cell line. The inhibition of the GST pi activity was dose dependent. Kinetic studies never revealed competitive inhibition. A parabolic inhibition was found with GSH as the variable substrate. The heavy metals are spontaneously conjugated with GSH and cysteine, but interact with GST pi by direct binding to this protein. This binding could have a protective function against heavy metals.
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PMID:In vitro interaction of mercury, copper (II) and cadmium with human glutathione transferase pi. 221 73

Transfection of a human pSV2 (copper-zinc) superoxide dismutase expression vector into murine fibroblasts resulted in stable clones producing increased amounts of copper-zinc superoxide dismutase. A marked increase in endogenous glutathione peroxidase activity (up to 285%) and a smaller increase in glutathione transferase activity (up to 16%) also occurred. Manganese superoxide dismutase activity was decreased in all clones, whereas catalase and NADPH reductase activities were not affected. Alterations in glutathione peroxidase and manganese superoxide dismutase activities correlated with increases in copper-zinc superoxide dismutase activity. Whereas all clones were resistant to paraquat, a direct correlation between copper-zinc superoxide dismutase activity and resistance to paraquat did not exist. In agreement with previous reports clones expressing the highest copper-zinc superoxide dismutase activity did not display the highest resistance to paraquat. However, there was a direct correlation between the increase in glutathione peroxidase activity and paraquat resistance (p less than 0.002).
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PMID:Alteration of endogenous glutathione peroxidase, manganese superoxide dismutase, and glutathione transferase activity in cells transfected with a copper-zinc superoxide dismutase expression vector. Explanation for variations in paraquat resistance. 235 46


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