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)

Photoemissive excited species are produced by the horseradish peroxidase (HRP)-catalyzed oxidation of reduced glutathione (GSH), without exogenously added hydroperoxide under aerobic conditions. The emitted low-level chemiluminescence consisted of two phases. Light emission occurred at wavelengths beyond 610 nm (greater than or equal to 90% intensity), indicative of singlet oxygen 1O2. Deuterium oxide enhanced photoemission 4.4-fold. Ascorbate inhibited chemiluminescence completely. In the absence of GSH or when GSH was replaced by the disulfide, no red chemiluminescence was observed. The glutathionyl radical GS. is most likely to be involved in both phases of light emission. Further, the superoxide radical plays a role, as substantiated by the inhibitory effect of superoxide dismutase. Both phases of photoemission were abolished by glutathione peroxidase; thus hydroperoxides are regarded as essential intermediates for the formation of excited species. Catalase abolished phase I and did not affect phase II. In contrast, glutathione S-transferase 1-2 (showing peroxidase activity towards organic hydroperoxides but not towards H2O2) inhibited phase II, whereas phase I was still present. Glutathione sulfonate and the disulfide GSSG were detected as oxidation products from GSH under conditions where phase II chemiluminescence was observed. HRP Compound III accumulated during the reaction. It is concluded that phase I is dependent on exogenously added or endogenously generated H2O2, whereas phase II does not require H2O2 but an organic peroxy species. A mechanism based on chain reactions involving oxygen addition to the thiyl radical is proposed. Sulfenyl peroxy species are suggested as transient intermediates in reactions finally leading to the generation of excited states such as singlet molecular oxygen.
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PMID:Excited species generation in horseradish peroxidase-mediated oxidation of glutathione. 301 81

The intracellular steady-state concentrations of hydrogen peroxide or superoxide anion were increased by inhibiting either catalase, glutathione peroxidase, or superoxide dismutase activities. Catalase was inhibited with aminotriazole while glutathione peroxidase activity was blocked by eliminating reduced glutathione after addition of either iodoacetamide diethylmaleate or phorone. The concentration of aminotriazole that stimulated chemiluminescence in 50% (60 mM) was very similar to the Ki for catalase activity (70 mM). Cyanide, an inhibitor of both catalase and superoxide dismutase, stimulated chemiluminescence in 50% at a concentration (0.15 mM) which is much closer from the Ki for superoxide dismutase (0.25 mM) than from the Ki for catalase (15 microM). The superoxide dismutase inhibitor diethyldithiocarbamate also increased chemiluminescence six- to ten-fold. Depletion of reduced glutathione stimulated spontaneous chemiluminescence when its concentration decreased below 4.5 mumol X g liver-1. The results shown herein suggest that the changes in the intracellular steady-state concentration occurring after inhibition of any antioxidant enzyme are responsible for the increased spontaneous chemiluminescence. Spontaneous chemiluminescence from intact cells may be used as a noninvasive method for monitoring intracellular free radical metabolism.
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PMID:Increased spontaneous chemiluminescence from liver homogenates and isolated hepatocytes upon inhibition of O2- and H2O2 utilization. 302 9

Cell number, protein, and phorbol myristate acetate (PMA)-induced H2O2 production were measured in cultured human peripheral blood monocytes for six days after exposure to varying doses of gamma-radiation. Both the number of adherent cells and the protein per dish decreased with increasing radiation doses. The dose of radiation decreasing the number of adherent cells by 37% on days 4 and 6 postirradiation was 29 Gy. Four hours postirradiation there was a small decrease in PMA-induced H2O2 production for doses of 7.5 Gy or greater; levels returned to normal by eight hours and increased at 24 hours postirradiation. By day 4 postirradiation significant increases in PMA-induced H2O2 production were noted at all radiation doses (2.5 to 50 Gy). This increase was not due to a shift in the PMA dose-response curve, a change in the time course of the PMA response, or an effect of decreased cell density on the assay system. Superoxide levels were not significantly changed in cells exposed to 20 Gy. Catalase, glutathione peroxidase, and superoxide dismutase levels also were unchanged. Culturing irradiated cells with gamma-interferon increased PMA-induced H2O2 release, which indicated that irradiated cells retained their capacity to respond to gamma-interferon. These data demonstrate that irradiation affects the PMA-induced H2O2 production of human monocytes in a time- and dose-dependent manner. An increase in the release of reactive oxygen intermediates by the macrophage may play a role in enhancing the deleterious effects of radiation in vivo.
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PMID:Exposure to gamma-irradiation increases phorbol myristate acetate-induced H2O2 production in human macrophages. 304 Jan 53

Prostaglandin H synthase, the primary enzyme in the pathway to the prostaglandins, requires the continued presence of a hydroperoxide activator for its enzyme activity. Phagocytic leukocytes from either humans or guinea pigs produced activator hydroperoxides in quantities sufficient to enhance prostaglandin synthesis in cells. Compounds that stimulated the oxidative burst (e.g., phorbol myristate acetate, opsonized zymosan, and N-formyl-L-methionyl-L-leucyl-L-phenylalanine) enhanced the overall production of the activators. Accumulation of activator(s) was promoted by exogenous Fe+3 (2 mumol/L), adenosine diphosphate (10 mumol/L), and unsaturated fatty acids (1 to 30 mumol/L) and was completely inhibited by glutathione peroxidase (0.5 U/ml). Catalase (500 U/ml) decreased the amount of activator by 70% when added during the incubation but by only 40% when added after the incubation. Thus, the activator appeared to be partly H2O2 and partly a lipid hydroperoxide. The addition of H2O2 in quantities similar to those produced by phagocytes increased prostaglandin formation by twofold in incubations with U937 cells and carbon 14-labeled arachidonic acid (2 mumol/L). These results indicate a new role for the oxygen metabolites from leukocytes in providing an intercellular signal that can stimulate prostaglandin synthesis.
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PMID:In vitro formation of activators for prostaglandin synthesis by neutrophils and macrophages from humans and guinea pigs. 309 22

This study examined the effects of gossypol acetic acid on the antioxidant defense system of the rat testis. In gossypol-treated animals testis catalase and glutathione peroxidase activities were decreased. Catalase and glutathione peroxidase are the two enzymes that protect against oxidative damage by hydrogen peroxide. Other antioxidants that were reduced in treated animals were glucose-6-phosphate dehydrogenase, superoxide dismutase, glutathione reductase, alpha-tocopherol, and ascorbate. Gossypol, a pigment of cottonseed and cottonseed products, causes infertility in humans and many animal species, but its mechanism of action is unknown. Gossypol is known to produce reactive oxygen species in vitro. Oxidative injury caused by the generation of reactive oxygen species and a compromised antioxidant defense system may be responsible for the antifertility effects of gossypol.
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PMID:Effects of gossypol on the antioxidant defense system of the rat testis. 319 Mar 61

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

In the mid-fifth instar larvae of the cabbage looper moth, Trichoplusia ni, the subcellular distribution of total superoxide dismutase was as follows: 3.05 units (70.0%), 0.97 units (22.3%), and 0.33 units (7.6%) mg-1 protein in the mitochondrial, cytosolic and nuclear fractions, respectively. No superoxide dismutase activity was detected in the microsomal fraction. Catalase activity was unusually high and as follows: 283.4 units (47.3%), 150.1 units (25.1%), 142.3 units (23.8%), and 22.9 units (3.8%) mg-1 protein in the mitochondrial, cytosolic, microsomal (containing peroxisomes), and nuclear fractions. No glutathione peroxidase activity was found, but appreciable glutathione reductase activity was detected with broad subcellular distribution as follows: 3.86 units (36.1%), 3.68 units (34.0%), 2.46 units (23.0%), and 0.70 units (6.5%) mg-1 protein in the nuclear, mitochondrial, and cytosolic fractions, respectively. The unusually wide intracellular distribution of catalase in this phytophagous insect is apparently an evolutionary adaptation to the absence of glutathione peroxidase; hence, lack of a glutathione peroxidase-glutathione reductase role in alleviating stress from lipid peroxidation. Catalase working sequentially to superoxide dismutase, may nearly completely prevent the formation of the lipid peroxidizing .OH radical from all intracellular compartments by the destruction of H2O2 which together with O2- is a precursor of .OH.
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PMID:Antioxidant enzymes of larvae of the cabbage looper moth, Trichoplusia ni: subcellular distribution and activities of superoxide dismutase, catalase and glutathione reductase. 324 4

The growth of mycobacteria on perfluorodecalin-modified media was shown to be accompanied by distinct alterations in the activity of the antioxidant enzyme system in M. bovis BCG and M. lufu. In M. bovis BCG the levels of glutathione transferase and glutathione peroxidase-hydrogen peroxidase activity are decreased by 45.47% and 100.88%, respectively. In M. lufu, on the contrary, the level of superoxide dismutase is increased by 42.23%, with no changes observed in the levels of glutathione transferase and glutathione peroxidases. The data obtained suggest physiological heterogeneity of mycobacteria and, thus, open prospects for the differential approaches to the problem of increasing the efficacy of in vitro cultivation of various mycobacterial species, including M. leprae.
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PMID:[Functional characteristics of the antioxidative system in mycobacteria grown on perfluorodecalin-modified media]. 328 44

Experiments were performed to investigate the effects of 60 min severe global ischemia followed by 30 min reperfusion on the antioxidant enzymatic system in the isolated perfused rat heart. Ischemia induced a significant increase of cytoplasmic and mitochondrial selenium-dependent glutathione peroxidase (EC 1.11.1.9) activity. In reperfused hearts, only the mitochondrial form showed a further significant increase. Glutathione reductase (EC 1.6.4.2) was increased in ischemic hearts, whilst the reperfused hearts showed a decrease towards the level found in aerobic hearts. Mitochondrial superoxide dismutase (EC 1.15.1.1) activity was depressed in ischemic as well as in reperfused hearts, though the cytoplasmic form was unmodified. Catalase (EC 1.11.1.6), glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and glutathione transferase (EC 2.5.1.18) activities were unchanged throughout the experiment. Ischemia and reperfusion induced a significant fall in tissue-reduced glutathione content concomitant with an increase of its oxidized form. We have also studied the mitochondrial inner membrane proteins for both molecular weight, with Coomassie blue, and thiol status, with monobromobimane stain, using a sodium dodecyl sulfate polyacrylamide gel electrophoresis technique. Neither ischemia nor reperfusion effected any relevant modification of the molecular weight of the mitochondrial inner-membrane proteins either in the presence or absence of a reducing agent. However, two of these proteins with an apparent molecular weight of 52,0000 and 12,000 showed a decrease in the monobromobimane stain, probably due to the oxidation of their thiol groups.
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PMID:Effect of ischemia and reperfusion on antioxidant enzymes and mitochondrial inner membrane proteins in perfused rat heart. 338 95

Significant pulmonary toxicity is associated with the use of nitrofurantoin; however, the mechanism of cellular toxicity remains poorly characterized. By using a novel in vitro red blood cell (RBC) chromium 51 cytotoxicity assay, cell injury induced by nitrofurantoin was quantified with normocatalasemic BALB/c RBCs and hypocatalasemic (but otherwise genetically identical) CCN RBCs as target cell populations. Nitrofurantoin at concentrations of 2 x 10(-4) and 4 x 10(-4) mol/L resulted in significant injury to normocatalasemic RBCs with a cytotoxic index (CI) of 21.7% +/- 3.7% and 65.3% +/- 3.7% (p less than 0.05, both comparisons). This injury was substantially increased when nitrofurantoin (2 x 10(-4) and 4 x 10(-4) mol/L was incubated with hypocatalasemic RBCs, resulting in CIs of 59.0% +/- 7.4% and 91.0% +/- 2.0% respectively (p less than 0.05, both comparisons with normocatalasemic RBCs). Direct oxidant-mediated cytotoxicity induced by either H2O2 or the superoxide anion radical (as generated by xanthine-xanthine oxidase) also resulted in more significant injury to hypocatalasemic RBCs than to normocatalasemic RBCs (p less than 0.05, both comparisons). Catalase levels of CCN RBCs were approximately 7% of control BALB/c RBC values; however, the activities of superoxide dismutase and glutathione peroxidase were identical in both populations of RBCs. This model, using genetically defined target cell populations, clearly demonstrates the importance of endogenous catalase in protecting against nitrofurantoin-induced cytotoxicity, suggesting that H2O2 is a critical intermediary in the direct cell injury mediated by the drug.
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PMID:Importance of hydrogen peroxide in nitrofurantoin-induced cytotoxicity: evidence from an inbred catalase-deficient strain of mice. 341 Nov 91


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