Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The activity of aortic glutathione peroxidase, a selenium-dependent enzyme, significantly decreased in rats 4 and 8 months after the injection of streptozotocin (STZ). Catalase activity was shown to occur at low levels in rat aorta and was not influenced by the diabetic state. Superoxide dismutase activity was less than detectable. The activity of selenium-dependent glutathione peroxidase in kidney, but not in lung and liver, increased in diabetic rats. Catalase and superoxide dismutase activities in the kidney were not altered. The plasma lipid peroxide value increased in diabetic rats. The selenium content in plasma of diabetic rats increased markedly while the increase in plasma glutathione peroxidase activities was insignificant. The observed abnormalities in plasma of STZ rats were improved by insulin treatment. The defects in glutathione peroxidase in the diabetic rat aorta were restored by insulin treatment. These results may suggest that the capacity of the antioxidative defense system in the aorta decreased in the diabetic state, and this may help clarify the mechanism of the pathogenesis of endothelial dysfunction associated with diabetes.
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PMID:Alterations of the plasma selenium concentrations and the activities of tissue peroxide metabolism enzymes in streptozotocin-induced diabetic rats. 321 28

Decomposition of hydrogen peroxide (H2O2 ) at physiological levels was studied in human erythrocytes by means of a recently developed sensitive H2O2 assay. The exponential decay of H2O2 in the presence of purified erythrocyte catalase was followed down to 10(-9) mol/L H2O2 at pH 7.4. H2O2 decomposition by purified erythrocyte glutathione peroxidase (GPO) could be directly observed down to 10(-7) mol/L H2O2 . No enzyme inhibition was observed at these low H2O2 concentrations. Catalase and GPO activities can be determined separately in a titrated mixture of purified enzymes, which simulates the conditions of H2O2 removal by the erythrocyte. Experiments with fresh human hemolysate allowed us to determine H2O2 decomposition by catalase and GPO using these enzymes in their original quantitative ratio. The different kinetics of these enzymes are shown: H2O2 decomposition by catalase depends linearly on H2O2 concentration, whereas that by GPO becomes saturated at concentrations above 10(-6) mol/L H2O2. Even at very low H2O2 concentrations GPO reaches only approximately 8% of the rate at which catalase simultaneously degrades H2O2. These data indicate an almost exclusive role for catalase in the removal of H2O2 in normal human erythrocytes.
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PMID:Direct evidence for catalase as the predominant H2O2 -removing enzyme in human erythrocytes. 938 16

The activities of superoxide dismutase, glutathione peroxidase and the contents of glutathione, malondialdehyde were examined in erythrocytes of streptozotocin induced diabetic rats. The above mentioned antioxidant systems of erythrocyte were determined after treatment of diabetic rats with superoxide dismutase, trolox, catalase and allopurinol. In erythrocytes of streptozotocin induced diabetic rats the activities of superoxide dismutase, glutathione peroxidase as well as the levels of reduced glutathione were lower whereas the contents of oxidized glutathione and malondialdehyde were higher than in controls. Superoxide dismutase and trolox treatment of diabetic rats resulted in an increase of erythrocyte glutathione peroxidase activities and in reduced glutathione levels. However the levels of oxidized glutathione decreased after treatment of diabetic rats with superoxide dismutase and trolox. Catalase and allopurinol administration did not have any influence on the activities of the investigated enzymes nor on the levels of glutathione in diabetic rats. The antioxidants under study did not cause any changes in the increased level of malondialdehyde in erythrocytes.
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PMID:Alternations in free radical erythrocyte-defense mechanisms in streptozotocin induced diabetic rats - effect of antioxidant treatment. 1033 67

Glutathione peroxidase (GPX) activity measured using tert-butyl hydroperoxide as a substrate detects solely cellular/classical GPX (cGPX) in rat liver and kidney, and extracellular/plasma glutathione peroxidase (EC-GPX) in rat serum. To investigate the effect of peroxisome proliferator on EC-GPX, we measured activities of GPX and catalase in rat liver, kidney and serum, and then we performed immunoblot and Northern blot analyses in the kidney. Rats were fed on a diet containing either 2% (w/w) di-2-ethylhexyl phthalate (DEHP) or 0.25% (w/w) clofibrate for two or three weeks, respectively. Catalase activity was increased 1.4-fold (p < 0.001) in the treated liver, but not in the kidney. GPX activity was decreased to 59.2% (DEHP) and 70.4% (clofibrate) of the control (p < 0.001) in the serum but was unaltered in the liver and kidney. The immunoreactivity for EC-GPX was also significantly decreased in the DEHP-treated kidney compared with the control. The mRNA levels of EC-GPX and cGPX were unaltered. The immunostaining for 4-hydroxy-2-nonenal, a maker of lipid peroxide, was more intense in the treated kidney compared with the control. These results suggest that EC-GPX is post-transcriptionally decreased by peroxisome proliferator through the oxidative stress in the renal tubules. This may be a new deleterious effect of an endocrine disruptor DEHP.
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PMID:Effect of peroxisome proliferator on extracellular glutathione peroxidase in rat. 1049 74

The aim of this study was to determine the effects of Hippophae rhamnoides L. extract (HRe-1) and also vitamin E as a positive control on nicotine-induced oxidative stress in rat blood, specifically alterations in erythrocyte malondialdehyde (MDA) level, activities of some erythrocyte antioxidant enzymes, and plasma vitamin E and A levels. The groups were: nicotine (0.5 mg/kg/d, intraperitoneal, i.p.); nicotine+vitamin E (75 mg/kg/d, intragastric, i.g.); nicotine+HRe-1 (1 ml/kg/d, i.g.); and control group (receiving only vehicles). There were 8 rats per group and the supplementation period was 3 weeks. Nicotine-induced increase in erythrocyte MDA level was prevented by both HRe-1 and vitamin E. Nicotine-induced decrease in erythrocyte superoxide dismutase (SOD) activity was prevented by HRe-1, but not vitamin E. HRe-1 increased the erythrocyte glutathione peroxidase (GSH-Px) activity compared with nicotine and the vitamin E groups. Catalase activity was not affected. Vitamin E supplementation increased plasma vitamin E level. Plasma vitamin A level was higher in both vitamin E and HRe-1 supplemented groups compared with nicotine and control groups. The results suggest that HRe-1 extract can be used as a dietary supplement, especially by people who smoke, in order to prevent nicotine-induced oxidative stress.
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PMID:Beneficial effects of Hippophae rhamnoides L. on nicotine induced oxidative stress in rat blood compared with vitamin E. 1223 Jan 3

The balanced presence of reactive oxygen species and antioxidants has a positive impact on sperm functions, oocyte maturation, fertilization, and embryo development in vitro. The mammalian oviduct is likely to provide an optimal environment for final gamete maturation, sperm-egg fusion, and early embryonic development. However, the expression and distribution of antioxidant enzymes in the bovine oviduct are poorly characterized. We analyzed the mRNA expression and enzymatic activities of major antioxidants glutathione peroxidase (GPx), superoxide dismutase (Cu,ZnSOD), and catalase in the bovine oviduct throughout the estrous cycle. The high levels of expression for GPx-3 in the isthmus were in contrast to expression of GPx-1 and GPx-2, which occurred mostly in the ampulla and infundibulum of the oviduct. The highest levels of mRNA expression for GPx-1 were observed toward the end of the estrous cycle before ovulation, whereas GPx-2 was mostly expressed at midcycle. Catalase and Cu,ZnSOD mRNA analyses revealed a homogenous expression along the oviduct. The highest levels of glutathione and enzymatic activities for GPx and catalase occurred at the middle (10-12 days) and end (18-20 days) of the estrous cycle, whereas total SOD activity remained constant throughout the estrous cycle in the oviductal fluids. These findings underscore the importance of hydrogen peroxide and hydroperoxide removal by GPx in the oviduct. The heterogeneous expression of antioxidants such as GPx along the oviduct is a possible indication of their physiological role in the events leading to successful fertilization and implantation in vivo.
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PMID:Antioxidant defenses are modulated in the cow oviduct during the estrous cycle. 1260 42

With the incessant challenge of exposure to the air we breathe, lung tissue suffers the highest levels of oxygen tension and thus requires robust antioxidant defenses. Furthermore, following injury or infection, lung tissue faces the additional challenge of inflammation-induced reactive oxygen and nitrogen species (ROS/RNS). Little is known about the identity or distribution of lung antioxidant enzymes under normal conditions or during infection-induced inflammation. Using a mouse model of influenza (H1N1 influenza virus A/PR/8/34 [PR8]) in combination with bioinformatics, we identified seven lung-abundant antioxidant enzymes: Glutathione peroxidase 3 (Gpx3), Superoxide dismutase 3 (Sod3), Transferrin (Tf), peroxyredoxin6 (Prdx6), glutathione S-transferase kappa 1 (Gstk1), Catalase (Cat), and Glutathione peroxidase 8 (Gpx8). Interestingly, despite the demand for antioxidants during inflammation, influenza caused depletion in two key antioxidants: Cat and Prdx6. As Cat is highly expressed in Clara cells, virus-induced Clara cell loss contributes to the depletion in Cat. Prdx6 is also reduced due to Clara cell loss, however there is a coincident increase in Prdx6 levels in the alveoli, resulting in only a subtle reduction of Prdx6 overall. Analogously, Gpx3 shifts from the basement membranes underlying the bronchioles and blood vessels to the alveoli, thus maintaining balanced expression. Taken together, these studies identify key lung antioxidants and reveal their distribution among specific cell types. Furthermore, results show that influenza depletes key antioxidants, and that in some cases there is coincident increased expression, consistent with compensatory expression. Given that oxidative stress is known to be a key risk factor during influenza infection, knowledge about the antioxidant repertoire of lungs, and the spatio-temporal distribution of antioxidants, contributes to our understanding of the underlying mechanisms of influenza-induced morbidity and mortality.
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PMID:Major shifts in the spatio-temporal distribution of lung antioxidant enzymes during influenza pneumonia. 2235 71