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

Three 6 week-old lambs were injected with carrier-free selenium-75 as sodium selenite initially and again after 6 days. One lamb received no further injections whereas the other two received injections of either vitamin E or unlabeled Na2SeO3 when the first selenium-75 injection was given. Selected tissues were removed at autopsy 10 days after the first injection. The cytosol from homogenates of these tissues was subjected to gel chromatography, and the elution profiles determined for radioactivity, protein content, and glutathione peroxidase activity using either hydrogen peroxide or cumene hydroperoxide as substrates. The selenium-75 was found to be distributed mainly between 2 different MW peaks. The larger MW seleno-peak (90,000) possessed both glutathione:hydrogen peroxide oxidoreductase, and glutathione:cumene hydroperoxide oxidoreductase activities, but the smaller MW seleno-peak (about 10,000) possessed no glutathione peroxidase activity. A peak of about 60,000 daltons containing only glutathione:cumene hydroperoxide oxidoreductase activity and no selenium-75 was found primarily in the liver and kidney. Vitamin E had no effect on the elution profiles. Selenium status of the animal had only a minor effect on the selenium-75 distribution in the cytosol, but had a marked effect on the absolute amount of the label taken up by tissues.
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PMID:Selenium proteins in ovine tissues: III. Distribution of selenium and glutathione peroxidases in tissue cytosols. 63 9

Metal-chelating agents inhibited platelet aggregation and the accompanying generation of rabbit aorta contracting and PG-like activities, when platelets were challenged with arachidonic acid. Inhibition required the presence of the chelating agents in the medium, and was insured by reagents avid for free or protein-bound copper. Catalase also prevented aggregation and generation of pharmacologically active substances; its activity was reversed by aminothiol agents and by Cu2+ and Zn2+, shown previously to potentiate the platelet effects of arachidonic acid. Inhibition by indomethacin was not prevented by amino-thiol drugs nor by Cu2+ or Zn2+. The catalase-induced inhibition was not affected by scavenging of thiol groups; this rules out, as a mechanism of action of catalase, the increased destruction of popoperoxides by glutathione peroxidase, which requires reduced glutathione as hydrogen donor. The results are compatible with the hypothesis that the agent that mediates platelet aggregation by arachidonic acid is a popoperoxide, requiring the presence either of H2O2 or of a similarly catalase-sensitive substance to be generated.
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PMID:Blockade by metal complexing agents and by catalase of the effects of arachidonic acid on platelets: relevance to the study of anti-inflammatory mechanisms. 117 85

Oxygen free radicals and hydroperoxides have been postulated to play a causal role in the aging process, implying that antioxidant enzymes may act as longevity determinants. Catalase (H2O2:H2O2 oxidoreductase; EC1.11.1.6) is the sole enzyme involved in the elimination of H2O2 in Drosophila melanogaster; glutathione peroxidase being absent. A genomic fragment containing the Drosophila catalase gene was used to construct transgenic Drosophila lines by means of P element-mediated transformation. Enhanced levels of catalase (up to 80%) did not prolong the life span of flies, nor did they provide improved protection against oxidative stress induced by hyperoxia or paraquat treatment. However, enhanced resistance to hydrogen peroxide was observed in the overexpressors.
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PMID:The effects of catalase gene overexpression on life span and resistance to oxidative stress in transgenic Drosophila melanogaster. 137 30

Erythrocyte antioxidants catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase were studied in cells harbouring different growth stages of Plasmodium falciparum. Catalase and superoxide dismutase showed significant decrease during parasite maturation indicating hampered metabolism of hydrogen peroxide and superoxide anions. Glutathione peroxidase also exhibited a downward trend during the growth of P. falciparum, while there was a moderate accumulation of reduced glutathione. These findings suggest decreased utilization of the reduction potential in detoxification of reactive oxygen species. The fall in all three antioxidant enzymes studied was highly significant (P less than 0.001) in erythrocytes with mature stages of the parasite (trophozoites, schizonts). The increased vulnerability of erythrocytes to damage, which parallels the growth phases of the parasite emphasizes the need for early treatment of P. falciparum malaria to minimise red cell destruction and the resulting anaemia.
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PMID:Plasmodium falciparum induced perturbations of the erythrocyte antioxidant system. 139 36

Injury to the gastrointestinal tract by oxygen dependent processes is important in ischemia, inflammatory bowel disease, and necrotizing enterocolitis. The Caco-2 cell line is an important tool in assessing various gastrointestinal functions and offers a unique opportunity to assess gastrointestinal oxidant metabolism on a cellular level. However, some Caco-2 cell functions change with time after confluence. To determine if antioxidant enzyme activity changes during differentiation, Caco-2 cells were grown to confluence, and superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and specific mRNA content were quantitated. With time after confluence the enzymes demonstrated a small, but statistically significant increase in activity. Neither superoxide dismutase nor glutathione peroxidase mRNA levels correlated with enzyme activity changes. Catalase mRNA levels increased as catalase activity increased. Thus, differentiated Caco-2 cells express superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase activities and the superoxide dismutase, glutathione peroxidase, and catalase genes. Superoxide dismutase activity and glutathione peroxidase activity do not correlate with mRNA levels, and suggest that regulation may be at a level other than transcription. The correlation between catalase activity and catalase mRNA suggests differentiation may occur at transcription. If Caco-2 cells are used to elucidate oxidative metabolism, changes in activities of antioxidant enzymes as a function of cell differentiation should be considered.
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PMID:Antioxidant enzymes in the differentiated Caco-2 cell line. 142 66

Ten patients with chronic renal failure (CRF) treated by hemodialysis (HD) were examined. All the patients demonstrated remarkable anemia. The red blood cell count was (2.7 +/- 0.2) x 10(12)/I the concentration of hemoglobin 79.5 +/- 5.6 g/l, on the average, hematocrit 23.2 +/- 1.8%. The content of malonic dialdehyde in the patients' red blood cells was far greater than in controls, amounting to 132% (per 1 ml of hemolysate), 134% (per 1 mg of protein) (p < 0.05). Catalase and glutathione peroxidase activity in the patients' red blood cells did not differ from that in controls. Superoxide dismutase activity reduced by 43% as compared to that in donors (p < 0.001). The authors review possible mechanisms of lipid peroxidation (LPO) and a decrease of antioxidant defense in red blood cells of CRF patients on hemodialysis. It is concluded that activation of LPO processes and the decrease of antioxidant defense produce a noticeable destructive effect on the integrity of the red blood cell membrane. They also influence the development of hemolysis.
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PMID:[Lipid peroxidation as a possible mechanism of erythrocyte damage in patients with chronic kidney failure on hemodialysis]. 144 Mar 43

The effect of iron-overload on both hepatic lipid peroxidation and chemiluminescence was studied in early stages after iron-dextran injection. Total hepatic iron content was markedly elevated over control values 2-6 h after iron dose. A 4-fold increase in light emission was detected after 4-6 h after iron injection. Plasma GOT, GPT and LDH activities were not affected by the treatment suggesting that cell permeability was not affected by necrosis. Increases in the generation of thiobarbituric acid reactive substances (TBARS) and chemiluminescence in liver homogenates, were determined as a function of time after iron administration, in the presence of NADPH as cofactor. Under the same experimental conditions, microsomal cytochrome P-450 content was decreased by 40%, 2 h after iron treatment. To evaluate liver antioxidant defenses, catalase, superoxide dismutase and glutathione peroxidase activities were determined. Glutathione peroxidase activity in the homogenate was not affected by the treatment. Catalase and superoxide dismutase activities declined by 25 and 36%, respectively, compared with control values 4 h after the iron dose. Our data suggest that lipid peroxidation occurs after mild iron overload even though the liver remains functional.
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PMID:Hepatic chemiluminescence and lipid peroxidation in mild iron overload. 147 93

The developmental expression of catalase, superoxide dismutase (both Mn-SOD and Cu/Zn-SOD) and glutathione peroxide activities were determined in human lung and liver from 10 wk gestation to 3 months following birth. Pulmonary superoxide dismutase and glutathione peroxidase activities did not change appreciably over this period. Catalase activity however, increased from 20.9 +/- 7.8 U/mg protein (n = 29) at 11-20 wk gestation to 73 +/- 27.5 U/mg protein (n = 30; P less than 0.001) following normal delivery (41-60 wk post-conceptual age). Lung catalase activity was temporally associated with the late gestational increase in the fractional content of lung DPPC (r = 0.79, P less than 0.01). In contrast with the lung, liver total superoxide dismutase activity increased from 2.5 +/- 0.6 U/mg protein (n = 27) between 11 and 20 wk gestation to 9.4 +/- 4.4 U/mg protein after term (n = 22; P less than 0.001). Since hepatic Mn-superoxide dismutase activity did not change over this period, the increase was attributed to elevated expression of Cu/Zn-superoxide dismutase. Liver glutathione peroxidase activities remained relatively constant during the same period, while hepatic catalase activity, although constant during gestation (60 +/- 15.6 microU/mg protein), increased significantly following birth (99.7 +/- 33.0 microU/mg protein; P less than 0.001). These results demonstrate that the developmental expression of antioxidant enzymes differs between tissues and that, unlike many commonly used laboratory species, only increased expression of catalase activity is associated with human lung development.
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PMID:Catalase, superoxide dismutase and glutathione peroxidase activities of lung and liver during human development. 152 75

The effects of ageing on the activity of copper-zinc superoxide dismutase (SOD), selenium-dependent and independent glutathione peroxidase (GSH-Px) and catalase in several areas of the brain in 3-, 12-, and 24-month-old rats were studied. In addition, the effects of a subacute intracerebroventricular treatment of NGF (1 microgram daily for 28 consecutive days) on SOD, GSH-Px, and catalase activity in the same areas of the brain were assessed. The effects of ageing on the activities of antioxidant enzymes varied considerably in the different brain areas studied. Copper-zinc SOD was alone in being unaffected by ageing. Intraventricular infusion of NGF significantly increased SOD activity in the prefrontal cortex, hypothalamus, caudate nucleus, and mesencephalon of 24-month-old rats. Selenium-dependent GSH-Px activity did not significantly change in 12-month-old rats but it increased in the lower brain stem of 24-month-old animals. In comparison to vehicle-treated rats, NGF significantly increased selenium-dependent GSH-Px activity in all brain areas studied in 12- and 24-month-old rats. Catalase activity decreased significantly in the majority of the brain areas studied in 12- and 24-month-old rats. NGF completely restored the fall in catalase activity in 12- and 24-month-old animals to levels similar to those occurring in young rats. In conclusion, the present experiments show, for the first time, that long-term intraventricular administration of NGF significantly increases in old animals the activity of key enzymes involved in the metabolic degradation of superoxide radicals and hydrogen peroxide.
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PMID:NGF restores decrease in catalase activity and increases superoxide dismutase and glutathione peroxidase activity in the brain of aged rats. 156 43

Quantification of intracellular and extracellular levels and production rates of reactive oxygen species is crucial to understanding their contribution to tissue pathophysiology. We measured basal rates of oxidant production and the activity of xanthine oxidase, proposed to be a key source of O2- and H2O2, in endothelial cells. Then we examined the influence of tumor necrosis factor-alpha and lipopolysaccharide on endothelial cell oxidant metabolism, in response to the proposal that these inflammatory mediators initiate vascular injury in part by stimulating endothelial xanthine oxidase-mediated production of O2- and H2O2. We determined a basal intracellular H2O2 concentration of 32.8 +/- 10.7 pM in cultured bovine aortic endothelial cells by kinetic analysis of aminotriazole-mediated inactivation of endogenous catalase. Catalase activity was 5.72 +/- 1.61 U/mg cell protein and glutathione peroxidase activity was much lower, 8.13 +/- 3.79 mU/mg protein. Only 0.48 +/- 0.18% of total glucose metabolism occurred via the pentose phosphate pathway. The rate of extracellular H2O2 release was 75 +/- 12 pmol.min-1.mg cell protein-1. Intracellular xanthine dehydrogenase/oxidase activity determined by pterin oxidation was 2.32 +/- 0.75 microU/mg with 47.1 +/- 11.7% in the oxidase form. Intracellular purine levels of 1.19 +/- 1.04 nmol hypoxanthine/mg protein, 0.13 +/- 0.17 nmol xanthine/mg protein, and undetectable uric acid were consistent with a low activity of xanthine dehydrogenase/oxidase. Exposure of endothelial cells to 1000 U/ml tumor necrosis factor (TNF) or 1 microgram/ml lipopolysaccharide (LPS) for 1-12 h did not alter basal endothelial cell oxidant production or xanthine dehydrogenase/oxidase activity. These results do not support a casual role for H2O2 in the direct endothelial toxicity of TNF and LPS.
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PMID:Responses of vascular endothelial oxidant metabolism to lipopolysaccharide and tumor necrosis factor-alpha. 156 24


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