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

We compared the mortality rate and the lung and liver histologic injury with the degree of tissue lipid peroxidation after zymosan-induced peritonitis. Male Wistar rats were given .75 or 1 mg/g of zymosan intraperitoneally and monitored for 24 h. Tissue lipid peroxides were measured as conjugated dienes and malondialdehyde (MDA) as were the antioxidants, ascorbic acid and catalase. Mortality rates for the .75 and 1 mg/g groups were 15 and 50%, respectively. In lung, the degree of increase in conjugated dienes and MDA was significantly greater in nonsurvivors than survivors. Ascorbic acid and catalase levels were also significantly decreased to a greater degree in the sicker animals with ascorbic acid decreased to a greater degree in the higher dose and sicker animals. The level of MDA corresponded with the degree of histologic change. Catalase decreased to a greater degree in liver than lung. We conclude that the degree of lung and liver lipid peroxidation correlates with the degree of inflammation induced tissue injury and mortality.
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PMID:Comparison between lung and liver lipid peroxidation and mortality after zymosan peritonitis in the rat. 774 53

Guinea pigs were fed for five weeks with two diets with different levels of vitamin C, low (33 mg of Vit C/Kg diet) and high (13,200 mg of Vit C/Kg of diet). Catalase was inhibited with 3-amino-1,2,4-triazole (AT) in half of the animals from each dietary group. AT caused an almost complete depletion of liver catalase activity (90%) in both dietary groups. Vitamin C supplementation increased total glutathione peroxidase activity and tissue vitamin C level and decreased levels of protein carbonyls and malondialdehyde (MDA) in both treated and non-treated animals. This vitamin C supplementation did not change any of the other antioxidant defences studied. Our results show that dietary vitamin C supplementation increases global antioxidant capacity and decreases endogenous oxidative damage in the guinea pig liver under normal non-stressful conditions. This supports the protective value of dietary antioxidant supplementation.
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PMID:Effect of dietary vitamin C and catalase inhibition of antioxidants and molecular markers of oxidative damage in guinea pigs. 792 Nov 63

When Escherichia coli was incubated with xanthine oxidase and acetaldehyde, the killing of E. coli was accelerated by iron-EDTA but inhibited by hematin or hemoglobin. On the other hand, when E. coli was incubated with human neutrophils in the presence of phorbol myristate acetate (PMA), all of these iron species at concentrations of a few micromolar accelerated the inactivation of neutrophils and in so doing protected the E. coli from being killed by the neutrophils. The inactivation of the neutrophils was accompanied by an increase in lipid peroxidation and by a decrease in viability measured with trypan blue. This inactivation was inhibited by scavengers such as deoxyribose, mannitol, or thiourea. Desferrioxamine B and 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) both inhibited the inactivation mediated by iron-EDTA, but had no effect on the hematin- or hemoglobin-mediated inactivation. Vanadium (vanadyl ion), an effective Fenton reagent, behaved in the same way as iron-EDTA relative to the effects of DMPO on neutrophil inactivation. These results led us to conclude that neutrophils were inactivated during PMA stimulation by OH radicals in the presence of iron-EDTA and by some other oxidizing species when hematin or Hb is present. Ascorbate enhanced the inactivation of neutrophils mediated by these iron species. Catalase was very effective in inhibiting neutrophil inactivation. Superoxide dismutase was not as effective but the combination with catalase was most effective.
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PMID:The effect of hemoglobin, hematin, and iron on neutrophil inactivation in superoxide generating systems. 813 43

There has not as yet been an integrated, comprehensive study of the responses of dermis and epidermis in vivo to a wide range of ultraviolet (UV) doses, encompassing all major antioxidants and a sensitive marker of oxidative damage. We have irradiated hairless mice with simulated solar light at doses of 2, 5, 12.5, and 25 J/cm2 combined UVA and UVB (0.8 to 10 MED) and measured enzymic and non-enzymic antioxidants as well as lipid hydroperoxides in both epidermis and dermis to elucidate the response of cutaneous antioxidant defense mechanisms to UV stress. Among the nonenzymic antioxidants two different dose-response patterns were seen. Ascorbate was rapidly depleted at doses between 0 and 5 J/cm2 but was less affected between 5 and 25 J/cm2. In contrast, glutathione, ubiquinol/one, and alpha-tocopherol levels remained approximately equal to control levels between 0 and 5 J/cm2, then decreased to varying degrees from 5 to 25 J/cm2; ubiquinol was almost completely depleted, whereas alpha-tocopherol dropped only 30%. The concentration of lipid hydroperoxides increased throughout the dose range. These results may be explained partly by direct destruction of some antioxidants by UV light, partly by the separate antioxidant functions of the compounds, and partly by recycling of some antioxidants (e.g., alpha-tocopherol) at the expense of others (e.g., ubiquinol). Even at the lowest dose (0.8 MED) lipid hydroperoxide formation was observed. Among the enzymic antioxidants, superoxide dismutase activity decreased significantly (to 63.6% of initial activity for epidermis and 51.5% for dermis at 25 J), whereas activities of glutathione peroxidase and glutathione reductase decreased slightly. Catalase activity decreased dramatically at doses above 5 J (to 11.8% of initial activity in epidermis and 27.7% in dermis at 25 J). The dramatic loss of catalase is almost entirely accounted for by direct destruction by the simulated solar light, but superoxide dismutase was unaffected by direct exposure; hence its destruction must be due to indirect effects, either mediated by free radicals or other harmful species formed upon irradiation. At low doses of UV light many components of the cutaneous antioxidant system were damaged, whereas at high doses all components were damaged and some were almost completely destroyed.
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PMID:Dose-response effects of acute ultraviolet irradiation on antioxidants and molecular markers of oxidation in murine epidermis and dermis. 815 Nov 22

Adriamycin-Fe(3+)-induced lipid peroxidation was enhanced by ascorbate at low concentrations. High concentrations of ascorbate also enhanced the peroxidation reaction, but only at an early stage. The initial rate of peroxidation depended upon the ratio of adriamycin-Fe2+/adriamycin-Fe3+ and the maximum rate was observed at the ratio of 1:1. These results suggest that the adriamycin-Fe(3+)-induced lipid peroxidation may be initiated by an adriamycin-Fe(2+)-oxygen-adriamycin-Fe3+ complex. Ascorbate also promoted bathophenanthroline-Fe2+ formation from adriamycin-Fe3+ in a dose-dependent manner. It seems likely that ascorbate influences the peroxidation reaction via the reduction of adriamycin-Fe3+. During the interaction of adriamycin-Fe3+ with ascorbate, deoxyribose was not degraded, suggesting that hydroxyl radical formation did not occur. In contrast, plasmid PM2 DNA was readily damaged during the interaction of adriamycin-Fe3+ with ascorbate. Catalase, mannitol and dimethylsulfoxide prevented DNA damage. No DNA damage occurred when the reaction was run under nitrogen gas, indicating that oxygen is involved.
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PMID:Effect of ascorbate on adriamycin-Fe(3+)-induced lipid peroxidation and DNA damage. 819 Jul 8

Catalase activity in cell cultures of fetal rat mesencephalon was decreased by 42 and 50%, respectively, after exposure to L-3,4-dihydroxyphenylalanine (L-DOPA, 100 microM) or dopamine (100 microM) for 48 h. Catalase activity was also decreased 21% by 10 microM hydroquinone. Ascorbic acid (200 microM), an agent that suppresses the autoxidation of L-DOPA and dopamine, blocked the anti-catalase effect of L-DOPA, but not that of dopamine. Inhibitors of the A and B forms of monoamine oxidase (20 microM clorgyline plus 20 microM pargyline) had no effect on the anti-catalase action of either L-DOPA or dopamine. The latter results suggest that products of the oxidative deamination of dopamine by monoamine oxidase are not involved in the suppression of catalase activity. However, autoxidation reactions of L-DOPA may play a role since ascorbate suppressed the anti-catalase effect of L-DOPA. On the contrary, the basis for the failure of ascorbate to similarly block the anti-catalase effect of dopamine is uncertain. L-DOPA and dopamine (25 microM) also inhibited crystalline catalase in solution after incubation for 1 h at neutral pH (40-50% inhibition). Inhibition was blocked by 0.45 M ethanol, indicating a need for autoxidation and the formation of compound II, which is an enzymatically inactive form of catalase. The ability to model the enzyme inhibition in purely chemical experiments indicates a probable mechanism for loss of enzymatic activity in cell cultures. Inhibition of catalase may contribute to cell damage during incubation of cultures with L-DOPA, dopamine, or other autoxidizable compounds.
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PMID:Inhibition of catalase in mesencephalic cultures by L-DOPA and dopamine. 911 32

In aqueous solutions containing Cu(II) ions and ascorbic acid, thiamine was observed to be oxidized to the fluorescent products thiochrome and oxodihydrothiochrome in neutral and acid media. At high initial concentrations of thiamine, thiochrome was practically the only product of thiamine oxidation. Catalase inhibited the oxidation rate approximately by 30-fold, whereas superoxide dismutase reduced the rate by only 2.5-fold. Aliphatic alcohols, glucose, and high concentrations of ascorbic acid effectively inhibited the production of thiochrome. The yield of thiochrome was also decreased in the presence of aliphatic amino acids, histidine, and particularly human serum albumin (HSA). With complete binding of copper ions by HSA, no formation of fluorescent products was observed. In neutral and acidic media under the action of hydroxyl radicals, thiamine formed a tricyclic semiquinone form which was then oxidized to thiochrome by superoxide anion or H2O2. Ascorbic acid played the main role in the reduction of Cu(II), whereas the contribution of superoxide anions was less significant. Cu(I) interacted with H2O2 to form hydroxyl radicals. The addition of H2O2 both to thiamine and to the mixture of thiamine and Cu(II) ions did not lead to significant production of thiochrome in neutral and acidic media.
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PMID:Thiamine oxidative transformations catalyzed by copper ions and ascorbic acid. 948 73

Chlorins are cyclic tetrapyrrole derivatives of great interest for use in photodynamic therapy. We have found that horseradish peroxidase (EC 1.11.1.7) (HRP) can convert deuteroporphyrin IX (Deutero) into chlorins. Some characteristics of this enzymatic transformation were investigated. The formation of chlorins was determined spectrophotometrically by monitoring the change in absorbance in the Q-band region (638 nm). The reaction occurred without addition of H2O2 and had a pH optimum of 7.5. The presence of thiol-containing reductants, with a great preference for reduced glutathione, was required and could not be substituted by adding H2O2. Ascorbic acid acted as a potent inhibitor of the reaction, while other organic acids (citric and benzoic) had little to no inhibitory effect. The requirement for O2 was suggested by the inhibitory effect of sodium hydrosulfite and was confirmed by carrying the assay in nitrogen-saturated solutions. Though the reaction occurred without adding H2O2, low amounts of H2O2 (3-30 microM) were stimulatory to the assay. However, concentrations of 300 microM H2O2 or higher were inhibitory. Similarly, light was not required, but was stimulatory at low levels and inhibitory at high levels. Catalase and deferoxamine were inhibitory, but superoxide dismutase and mannitol had no effects. Kinetic analysis and respiratory studies suggest that HRP may initially react with reduced glutathione in a reaction that does not consume much oxygen. The ensuing steps, probably involving an oxygen free radical and porphyrin radical intermediates, consume a large amount of O2 to oxidize Deutero into chlorin.
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PMID:Horseradish peroxidase-dependent oxidation of deuteroporphyrin IX into chlorins. 950 Aug 44

The reactions of steroid hormone biosynthesis are accompanied by formation of oxygen radicals. We determined the levels of some antioxidants and antioxidative enzymes at different developmental stages of bovine corpora lutea to examine their correlation with steroidogenic status. Plasma progesterone concentrations of estrous cycle synchronized cows increased until day 16, and then decreased rapidly during luteal regression. The levels of steroidogenic cytochrome P450scc and adrenodoxin paralleled the changes in plasma progesterone. Among the antioxidative enzymes examined, the SOD and catalase activities showed patterns most similar to plasma progesterone. Catalase and SOD activities increased 6-8 fold from day 6 to 16 of the estrous cycle and then decreased during the luteal regression. Ascorbate and beta-carotene showed low but significant correlation with P450scc and plasma progesterone levels. The profiles of two lipophilic antioxidants in corpora lutea were very different. beta-carotene concentration increased by approximately 6 fold from day 6 to 16, and decreased in regressive tissue. alpha-tocopherol showed a 3 fold increase between days 6 and 9 followed by a rapid decrease. Thus, at the peak of steroidogenesis at mid-luteal phase alpha-tocopherol levels decreased, but beta-carotene levels increased. The correlation between the levels of some antioxidant enzymes and compounds with progesterone levels indicates that antioxidative mechanisms are activated to cope with steroidogenesis dependent oxyradical formation in the bovine corpus luteum.
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PMID:Antioxidant capacity is correlated with steroidogenic status of the corpus luteum during the bovine estrous cycle. 954 62

Scission of plant cell wall polysaccharides in vivo has generally been assumed to be enzymic. However, in the presence of l-ascorbate, such polysaccharides are shown to undergo non-enzymic scission under physiologically relevant conditions. Scission of xyloglucan by 1 mM ascorbate had a pH optimum of 4.5, and the maximum scission rate was reached after a 10-25-min delay. Catalase prevented the scission, whereas added H2O2 (0.1-10 mM) increased the scission rate and shortened the delay. Ascorbate caused detectable xyloglucan scission above approx. 5 microM. Dehydroascorbate was much less effective. Added Cu2+ (>0.3 microM) also increased the rate of ascorbate-induced scission; EDTA was inhibitory. The rate of scission in the absence of added metals appeared to be attributable to the traces of Cu (2.8 mg.kg-1) present in the xyloglucan. Ascorbate-induced scission of xyloglucan was inhibited by radical scavengers; their effectiveness was proportional to their rate constants for reaction with hydroxyl radicals (.OH). It is proposed that ascorbate non-enzymically reduces O2 to H2O2, and Cu2+ to Cu+, and that H2O2 and Cu+ react to form .OH, which causes oxidative scission of polysaccharide chains. Evidence is reviewed to suggest that, in the wall of a living plant cell, Cu+ and H2O2 are formed by reactions involving ascorbate and its products, dehydroascorbate and oxalate. Systems may thus be in place to produce apoplastic .OH radicals in vivo. Although .OH radicals are often regarded as detrimental, they are so short-lived that they could act as site-specific oxidants targeted to play a useful role in loosening the cell wall, e.g. during cell expansion, fruit ripening and organ abscission.
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PMID:Oxidative scission of plant cell wall polysaccharides by ascorbate-induced hydroxyl radicals. 960 Oct 81


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