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)

Coenzymes participate in many of the enzyme analyses performed in the clinical laboratory. Supplementation of assay systems with optimal levels of coenzymes has recently been recommended as part of efforts to achieve interlaboratory standardization of enzyme measurements. Aspartate aminotransferase and alanine aminotransferase require pyridoxal phosphate for expression of enzyme activity. The role of this coenzyme in enzymatic transamination and the effects of its supplementation on the clinical estimation of these two enzymes is reviewed. Other coenzymes discussed are flavins, coenzymes for glutathione reductase, glucose oxidase, cholesterol oxidase and diaphorase, as well as thiamine pyrophosphate, coenzyme for transketolase. Catalase and peroxidase are used as examples of hemoproteins utilized in clinical measurements. Two peptide coenzymes, colipase and glutathione, are also considered. Measurement of apoenzyme stimulation upon supplementation with specific coenzymes is discussed as a valuable technique for quantitative coenzyme measurements or assessment of vitamin nutritional status.
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PMID:Review: the role of coenzymes in clinical enzymology. 33 88

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

Endogenous hydrogen peroxide (H2O2) release from aortic endothelial cells was studied in the presence of antioxidant enzyme inhibitors, mitochondrial inhibitors, a microsomal cytochrome P-450 inhibitor, and after oxidative stress induced with H2O2 or menadione. Extracellular H2O2 generation was determined spectrofluorometrically using 3-methoxy-4-hydroxy phenylacetic acid, and intracellular H2O2 production (in or near peroxisomes) was measured indirectly using aminotriazole, which inactivates catalase in the presence of H2O2. Extracellular H2O2 release was 0.079 +/- 0.005 nmol/min/mg protein in Hanks' balanced salt solution, was constant during a 120-min incubation period, and was not affected by the cell passage number. The half-life for catalase inactivation with aminotriazole was 23 min. Inhibition of catalase, glutathione reductase, or gamma-glutamylcysteine synthetase did not change the rate of extracellular release of H2O2. Furthermore, inhibition of the mitochondrial respiratory chain (rotenone, antimycin A) or microsomal cytochrome P-450 (8-methoxypsoralen) did not change extracellular H2O2 release or intracellular H2O2 production (at peroxisomes) by endothelial cells or cells in which glutathione reductase was inactivated. When the cells were exposed to exogenous H2O2 (30 microM), extracellular H2O2 was scavenged primarily by the glutathione redox pathway. Exogenously added H2O2 (100 microM) changed intracellular H2O2 production (in or near peroxisomes) only when the glutathione redox cycle was inactivated. Menadione (20 microM), which undergoes intracellular redox cycling, increased extracellular H2O2 release almost 4-fold to 0.3 nmol/min/mg protein. Furthermore, menadione increased peroxisomal H2O2 levels and decreased the half-life for catalase inactivation in the presence of aminotriazole to 13 min. Catalase inhibition increased extracellular H2O2 release during menadione treatment, indicating that H2O2 can diffuse across the plasma membrane during oxidant stress.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Regulation of hydrogen peroxide generation in cultured endothelial cells. 154 Mar 80

The role of different antioxidant pathways in cultured rat pleural mesothelial cells was studied by exposing the cells to various hydrogen peroxide (H2O2) concentrations and by measuring H2O2 cell cytotoxicity and the capacity of the cells to scavenge H2O2. The antioxidant enzymes, glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase, and catalase were analyzed biochemically. Catalase and CuZn superoxide dismutase were localized by immunocytochemistry. To enable investigation of the glutathione redox cycle and catalase pathways, glutathione reductase was inactivated with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and catalase was inactivated with aminotriazole. When the cells were exposed to a low, sublethal (0.030 mM) H2O2 concentration, glutathione reductase but not catalase inactivation resulted in a decreased capacity to remove H2O2 from the extracellular medium. When the cells were exposed to a high (0.25 mM) H2O2 concentration, H2O2-scavenging capacity decreased remarkably when catalase was inactivated. When the cells were exposed to 0.1 to 0.5 mM H2O2, cell cytotoxicity (lactate dehydrogenase release) increased significantly if glutathione reductase was inactivated; catalase inactivation resulted in a significant cytotoxicity only at high (greater than or equal to 0.25 mM) H2O2 concentrations. Immunocytochemical studies showed that the cells, both in situ and in vitro, contained low amounts of catalase. This suggests that the results of the catalase-inhibition studies are probably not due to a change in the characteristics of the cells in culture. 3-Aminobenzamide is a compound that is known to prevent NAD depletion through inhibition of poly(ADP-ribose) polymerase during oxidant stress. When intact cells were treated with different antioxidants and exposed to 0.5 mM H2O2, both catalase and 3-aminobenzamide protected the cells completely.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Antioxidant defense mechanisms in cultured pleural mesothelial cells. 162 38

Erythrocyte catalase, reduced glutathione, glutathione peroxidase and glutathione reductase were determined in 17 normal black controls, 8 subjects with Hb AC, 12 with Hb SC, 1 with Hb CC and 18 patients with sickle cell anemia. Catalase and glutathione peroxidase activities were decreased in sickle cell anemia. Reduced glutathione and glutathione reductase activity were significantly lower in subjects with Hb C (AC, CC, SC). Differences were observed between Hb C, Hb S and Hb A as regards red cell dehydration, intracellular crystallization, enhanced potassium efflux, an increased number of titratable SH groups in Hb C and the binding of Hb C to band 3 on the inner membrane surface. A decrease in reduced glutathione, probably due to inhibition or decreased synthesis of glutathione reductase, was also observed. All these factors may determine oxidation of Hb C, possibly contributing to the hemolysis in patients with Hb C disease.
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PMID:Decreased reduced glutathione and glutathione reductase activity in subjects with hemoglobin C. 194 19

Because the developing brain is subject to high oxygen tension and lacks a functional bloodbrain anti-oxidant protection is important to development in the brain. The levels of superoxide dismutase, copper-zinc superoxide dismutase, manganese superoxide dismutase, catalase, glutathione and related enzymes, namely, glutathione reductase and glutathione peroxidase were determined in rat brain at various stages of development. The levels of thiobarbituric acid reactive products, indicative of lipid peroxidation, were very low at birth and increased to adult levels by the 16th day after birth. Brain glutathione levels displayed significant variations during the first 2 weeks after birth but not thereafter. Catalase activity in developing brain slowly increased over 45 days. Total superoxide dismutase activity in 1-day-old rat brain, 80% of the adult rat brain level, subsequently decreased on day 6. Total superoxide dismutase activity, however, increased again in 10-day-old rats and remained constant thereafter. While the developmental pattern of manganese superoxide dismutase was similar to that of the total superoxide dismutase, the copper-zinc superoxide dismutase levels were low at birth and reached adult levels on the 10th day after birth. There was no variation in glutathione reductase and peroxidase levels except for a decrease on day 16 of glutathione reductase and slow increase in adult levels by day 28. The present findings suggest that the overall levels of antioxidant enzymes in the developing brain are comparable to a large extent to those present in the adult brain. In contrast to the developing brain, hepatic levels of glutathione, total superoxide dismutase, manganese superoxide dismutase are significantly lower at birth and increase during development.
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PMID:Free radical scavenging systems in developing rat brain. 205 19

Catalase inhibition leads to an increase in the t 1/2 for hydrogen peroxide loss from the anterior chamber and increased tissue damage. BCNU (1,3-bis-(2-chloroethyl)-l-nitrosourea) and BSO (buthionine sulfoxamine) were used to suppress glutathione reductase and glutathione synthesis, respectively. Intravitreal BSO (1 to 4 mg) reduced total glutathione levels of iris by 80%, and aqueous glutathione levels by 70%. BSO caused the t 1/2 for hydrogen peroxide disappearance from the anterior chamber to increase after 10 microliters of 10 mM peroxide was injected intracamerally but not after 25 or 50 mM peroxide injections. Catalase inhibition, however, had more influence at 50 mM than with 10 or 25 mM injections. The glutathione redox system is operative at low aqueous hydrogen peroxide concentrations and catalase is of greater importance at higher peroxide concentrations.
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PMID:Role of glutathione in the regulation of anterior chamber hydrogen peroxide. 210 Jan 69

Electron spin resonance (ESR) measurements provide evidence for the formation of Cr(V) intermediates in the enzymatic reduction of Cr(VI) by glutathione reductase (GSSG-R) in the presence of NADPH, indicating an initial single-electron transfer step in the reduction mechanism. Depending on the pH, at least two different Cr(V) species are generated which are relatively long-lived. In addition, we have detected the hydroxyl (.OH) radical formation during the GSSG-R catalyzed reduction of Cr(VI) by spin trapping, employing 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (4-POBN) as spin traps. Superoxide dismutase (SOD) causes only a minor effect on the .OH radical and Cr(V) formation, indicating that the O2- is not significantly involved in the reaction mechanism. Catalase enhances the Cr(V) formation and substantially inhibits the .OH radical formation, indicating the involvement of hydrogen peroxide (H2O2) in the reaction mechanism. Addition of H2O2 suppresses Cr(V) and enhances the .OH radical formation. Measurements involving N-ethylmaleimide show that the Cr(V) species, produced enzymatically by the reduction of Cr(VI) by GSSG-R, react with H2O2 to generate .OH radicals, which might participate in the initiation of Cr(VI) carcinogenicity.
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PMID:One-electron reduction of chromate by NADPH-dependent glutathione reductase. 217 78

The effects of cell-free generated oxidants on migrating and developing stages of Schistosoma mansoni were investigated and the levels of antioxidant enzymes and of glutathione were determined for each stage. Schistosomula and 2-week-old parasites recovered from the livers of infected mice showed similar susceptibility to killing by added hydrogen peroxide and t-butylhydroperoxide. However, when glucose (0.5 mM)-glucose oxidase (2.5 mU ml-1) and xanthine (0.5 mM) or hypoxanthine (0.5 mM)-xanthine oxidase (5.0 mU ml-1) systems were used to generate hydrogen peroxide and oxygen free-radicals, schistosomula were more susceptible to oxidative killing than the 2-week-old parasites. The 4- and 8-week-old worms were more resistant to oxidants than all of the younger stages. High levels of superoxide dismutase (16.2-24.8 U mg-1 protein) were present in all stages. Catalase was not detected. Glutathione peroxidase activity with cumene hydroperoxide as substrate was not detectable in the schistosomula but the activity was present in the 2-week-old parasites. However, hydrogen peroxide-sensitive glutathione peroxidase activity was present in all the stages with a threefold difference in activity between schistosomula and the adult stages. Glutathione-s-transferase activity was significantly lower in the schistosomula, lung stages, and the 2-week-old parasites than in the older stages. Progressive increases in the levels of glutathione reductase and glutathione were also observed with development. The differences in the levels of antioxidants between different stages of development may partly explain the increase in resistance to oxidant-mediated damage as the parasite develops.
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PMID:Schistosoma mansoni: levels of antioxidants and resistance to oxidants increase during development. 232 92

Over the last few years a remarkable progress has been made in the understanding of parasites biochemistry, molecular biology, and immunology. This progress is especially encouraging in that emphasis on drug development is shifting from random screening towards a more rational approach. A number of peculiar aspects characteristic of parasites which are not present in other organisms and that might be exploitable for the design of specific agents have been described recently. One of these aspects is their deficiency in defense mechanisms against oxygen toxicity. Catalase is absent in many parasites. Distinct superoxide dismutases have been detected and specific inhibitors of these enzymes have been investigated. Glutathione is absent in some anaerobic protozoa. Peroxidase and reductase activities dependent on a glutathione-spermidine cofactor termed trypanothione have been detected in several trypanosomatids and apparently replace the glutathione peroxidase-glutathione reductase system of other eukaryotic cells. Free radical intermediates have been shown to be involved in the reaction of enzymes present in anaerobic protozoa. In addition, a number of antiparasitic agents have been shown to exert their actions through a free radical metabolism: nitro compounds used against trypanosomatids, anaerobic protozoa and helminths; crystal violet used in blood banks to prevent blood transmission of Chagas' disease; the antimalarial primaquine, chloroquinine, and quinhasou; and quinones active in vitro and in vivo against different parasites.
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PMID:Sensitivity of parasites to free radical damage by antiparasitic drugs. 240 32


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