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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Catalase activity was determined in human semen by measuring the oxygen burst with a Clark electrode, after H2O2 addition. Significant catalase activities (mean +/- SD) were found in migrated, motile spermatozoa (44 +/- 17 nmoles O2/min/10(8) cells) and in seminal plasma of normozoospermic men (129 +/- 59 nmoles O2/min/ml). It has been demonstrated that seminal catalase originated from prostate; however, its activity was not correlated with the usual prostatic markers (such as citric acid and zinc). Our data suggest a multiglandular function secreted by this organ. The catalase activities measured in seminal samples from asthenozoospermic, infertile men were found lower than those from normozoospermic subjects. The understanding of the relative contribution of the different enzyme systems against O2 toxicity (superoxide dismutase, catalase, glutathione peroxidase) seem to be a priority area of research to understand disturbances of sperm function.
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PMID:Catalase activity in human spermatozoa and seminal plasma. 279 57

Relative resistance to oxygen toxicity in newborn animals (compared to adults) has been associated with increased antioxidant enzymes and glutathione in lung homogenate. The cell type(s) involved in this increase is unknown. We investigated the effect of hyperoxia in vitro and in vivo on the following antioxidants (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and glutathione) in alveolar type II cells from neonatal rats. Type II cells were exposed to 95% oxygen or air for 48 h in vitro. When expressed per microgram DNA, all the antioxidants except catalase increased during in vitro incubation; only glucose-6-phosphate dehydrogenase and glutathione increased when expressed per mg protein. None of the antioxidants was higher in oxygen-exposed cells than in air-exposed cells. Neonatal rats were exposed to 100% oxygen or air in vivo for 4 d before determination of antioxidants in lung homogenate supernatant and alveolar type II cells. Catalase, glutathione peroxidase, and glutathione reductase were higher but glucose-6-phosphate dehydrogenase and glutathione were lower in type II cells than in lung homogenate from control animals. Alveolar type II cell glucose-6-phosphate dehydrogenase and glutathione were increased but catalase and glutathione reductase were decreased by exposure to hyperoxia. We conclude that the oxygen-induced increase in whole lung antioxidants is not explained by alveolar type II cell hypertrophy or increased antioxidants within type II cells during hyperoxia.
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PMID:Effect of hyperoxia on antioxidants in neonatal rat type II cells in vitro and in vivo. 281 89

Evidence has been obtained that implicates the generation of reactive oxygen species as an early and critical event in the promotion of neoplastic transformation in mouse JB6 cells. The time courses for specific inhibition by CuZn-superoxide dismutase (CuZn-SOD) of the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced promotion of neoplastic transformation in JB6 cells and for changes in antioxidant enzyme activities associated with TPA-exposure were examined. The antipromoting effect of CuZn-SOD was found to be critically dependent on the time of addition of CuZn-SOD relative to the start of a 14-day exposure of cells to TPA. Treatment of JB6 P+ Clone 22 and Clone 41 cells with CuZn-SOD for 18 h before, simultaneously with or up to 1 h after exposure to TPA, all inhibited promotion of transformation maximally. Delay of addition of CuZn-SOD by 2 h or more after the start of TPA treatment resulted in a marked decrease in the promotion inhibitory effect. CuZn-SOD added 24 or 48 h after TPA had no effect on promotion of transformation. Exposure of JB6 cells to 0.2- (superoxide anion radical) generated exogenously by the aerobic xanthine oxidase reaction resulted in promotion of neoplastic transformation that was prevented by concurrent addition of CuZn-SOD. Taken together these studies provide evidence that increased superoxide anion generation within the first 2 h following TPA exposure is an essential event in promotion of transformation in JB6 cells. Upon TPA exposure, JB6 Clone 41 cells exhibited time-specific activity changes in the cellular SOD, glutathione peroxidase (GSH-Px), and catalase. SOD and GSH-Px activities were reduced to 54% and 26% respectively of basal levels within 2 h of TPA treatment. GSH-Px activity recovered to basal levels within 4 h and CuZn-SOD within 48 h. Catalase activity was maximally reduced to 50% of basal within 1 h after TPA treatment and rebounded to greater than basal levels within 4 h. It is postulated that a c-kinase-dependent event induces rapid elevation of superoxide anion following TPA exposure and that this leads to reduced activity of antioxidant enzymes. Since antipromotion by exogenous CuZn-SOD is effective only during the first 2 h following TPA exposure, this suggests that the promotion-relevant 0.2- elevation is transient.
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PMID:Early superoxide dismutase-sensitive event promotes neoplastic transformation in mouse epidermal JB6 cells. 282 3

Non-pigmented epithelial (NPE) cells and pigmented epithelial (PE) cells were dissociated from bovine ciliary processes by brief digestion with pronase and grown in a culture medium containing high fetal bovine serum for at least 25 generations. Both types of cells grown to confluence showed the presence of intermediate junctions with associated tonofilaments. PE cells were distinguished from NPE cells by pigmentation during the early passages. Gamma-glutamyl transpeptidase activity was associated almost exclusively with NPE cells and proved to be a useful enzymatic marker to distinguish NPE from PE. A comparison was made between NPE and PE cells as to the levels of enzymes involved in the detoxification of active oxygen species. Catalase, Se-dependent glutathione peroxidase and superoxide dismutase activities were significantly higher in NPE than in PE cells. The results suggest that NPE cells play the major role in detoxification of active oxygen species during aqueous humor formation.
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PMID:Bovine non-pigmented and pigmented ciliary epithelial cells in culture: comparison of catalase, superoxide dismutase and glutathione peroxidase activities. 290 72

The selenium-dependent glutathione peroxidase activities of three mammalian cell lines, HT29, P31, and N-18, cultured in medium with low serum content, increased about 2-, 5-, and 40-fold, respectively, after supplementation with 100 nM selenite. Catalase, CuZn superoxide dismutase, and Mn superoxide dismutase activities were not generally influenced by selenite supplementation, and there was only a minor nonselenium-dependent glutathione peroxidase activity in the investigated cell lines. Gamma-irradiated control and selenite-supplemented cells showed no changes in the surviving fractions, as estimated by clonogenic survival or [3H]-thymidine uptake, nor were there any significant differences between the two groups in the induction of DNA strand breaks after gamma irradiation under repairing (37 degrees C) or nonrepairing (0 degrees C) conditions. The results suggest that selenium-dependent glutathione peroxidase does not contribute significantly to the radiation resistance of cultured mammalian cells.
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PMID:Selenite-induced variation in glutathione peroxidase activity of three mammalian cell lines: no effect on radiation-induced cell killing or DNA strand breakage. 292 76

Culture medium of lymphocyte cultures that have been exposed to the superoxide generating system hypoxanthine plus xanthine oxidase (X-XO) contains substances with chromosome damaging properties. This is demonstrated by the ability of ultrafiltrates of such culture media to induce chromosomal aberrations and sister chromatid exchanges in the lymphocytes of blood test cultures. Culture medium becomes active about 15 hours after the addition of X-XO and stimulation by phytohemagglutinin. Concomitant with the accumulation of clastogenic material, assays for conjugated dienes and thiobarbituric acid-reactive material which measure lipid-peroxidation become positive in the culture media. When cells are pretreated with superoxide dismutase or glutathione peroxidase before the addition of X-XO neither clastogenic substances nor lipid peroxidation products are detected. Catalase is a less efficient protector.
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PMID:Treatment of lymphocyte cultures with a hypoxanthine-xanthine oxidase system induces the formation of transferable clastogenic material. 301 71

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


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