Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UNIPROT:P04040 (
Catalase
)
3,577
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
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.
...
PMID:Effect of ischemia and reperfusion on antioxidant enzymes and mitochondrial inner membrane proteins in perfused rat heart. 338 95
Catalase
(H2O2:H2O2 oxidoreductase, EC 1.11.1.6) is of historical interest for having been the subject of some of the earliest investigations of enzymes. A feature of catalase that has been poorly understood for several decades, however, is the mechanism by which catalase remains active in the presence of its own substrate, hydrogen peroxide. We reported recently that catalase contains tightly bound NADPH. The present study with bovine and human catalase revealed that NADPH both prevents and reverses the accumulation of compound II, an inactive form of catalase that is generated slowly when catalase is exposed to hydrogen peroxide. Since the effect of NADPH occurs even at NADPH concentrations below 0.1 microM, the protective mechanism is likely to operate in vivo. This discovery of the role of catalase-bound NADPH brings a unity to the concept of two different mechanisms for disposing of hydrogen peroxide (catalase and the
glutathione reductase
/peroxidase pathway) by revealing that both mechanisms are dependent on NADPH.
...
PMID:The function of catalase-bound NADPH. 380 1
The ability of aurothioglucose and D(-)-penicillamine hydrochloride to inhibit selenium-dependent glutathione peroxidase (SeGSH-Px) in vitro and to increase exudative diathesis in vitamin E-deficient chickens was studied. Aurothioglucose and penicillamine competitively inhibited SeGSH-Px in inverse proportion to the concentration of hydrogen peroxide and reduced glutathione, respectively, in chick liver postmitochondrial supernatant assay preparations. Neither drug inhibited
glutathione reductase
or superoxide dismutase at the concentrations tested; however, both inhibited catalase in a semilogarithmic fashion. This was true for both the purified bovine enzyme and chick liver homogenate. Aurothioglucose and penicillamine injected subcutaneously at the back of the neck increased exudative diathesis in vitamin E-deficient chickens fed 0.1 ppm Se, and effectively overcame the protective effect of selenium 72 h after injection in chicks fed vitamin E-free, low selenium diets supplemented with 0.0-0.1 ppm Se. Assays of plasma and of liver, lung and kidney postmitochondrial supernatants indicated that all observed reductions in SeGSH-Px activity preceded increases in exudative diathesis. Plasma and liver SeGSH-Px activities were lower at early times (6-24 h) after treatment with high doses of either drug. Lung SeGSH-Px activities were only lower in chicks receiving 240 mg penicillamine/kg 6 h after treatment; kidney SeGSH-Px activities were only lower in chicks treated with the highest dose of aurothioglucose 48 h after treatment. Brain SeGSH-Px activities were unaffected by drug treatment and the heart had higher SeGSH-Px activities only at 6 h after treatment with the highest dose of either drug compared to saline controls.
Catalase
activities in liver homogenates were only significantly altered by penicillamine; the highest dose caused the activity to be higher than that in saline-treated chicks. The cause of the lower SeGSH-Px activities could be either lower enzyme concentrations in tissues of the drug-treated groups and/or direct inhibition. Whatever the mechanism, it is concluded that exudative diathesis can be used to determine which drugs reduce SeGSH-Px activity in the chick.
...
PMID:Drug-induced changes in selenium-dependent glutathione peroxidase activity in the chick. 393 15
The catalase activity of cultured rat hepatocytes was inhibited by 90% pretreatment with 20 mM aminotriazole without effect on the activities of glutathione peroxidase or
glutathione reductase
, or on the viability of the cells over the subsequent 24 h.
Glutathione reductase
was inhibited by 85% by pretreatment with 300 microM 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) without effect on glutathione peroxidase, catalase, or on viability. Both pretreatments sensitized the hepatocytes to the cytotoxicity of H2O2 generated either by glucose oxidase (0.05-0.5 units/ml) or by the autoxidation of the one-electron-reduced state of menadione (50-250 microM). Aminotriazole pretreatment had no effect on the GSH content of the hepatocytes. BCNU reduced GSH levels by 50%. Depletion of GSH levels to less than 20% of control by treatment with diethyl maleate, however, did not sensitize the cells to either glucose oxidase or menadione, indicating that the effect of BCNU is related to inhibition of the GSH-GSSG redox cycle rather than to the depletion of GSH. With glucose oxidase, most of the cell killing in hepatocytes pretreated with either aminotriazole or BCNU occurred between 1 and 3 h. The antioxidant diphenylphenylenediamine (DPPD) had no effect on viability at 3 h.
Catalase
added to the culture medium 1 h after the addition of glucose oxidase prevented the cell killing measured at 3 h. The sulfhydryl reagents dithiothreitol (200 microM), N-acetyl-L-cysteine (4 mM), and alpha-mercaptopropionyl-L-glycine (2.5 mM) prevented the cell killing with exogenous H2O2 in hepatocytes sensitized by the inhibition of catalase or
glutathione reductase
. With menadione, there was no killing of nonpretreated hepatocytes at 1 h, and DPPD did not prevent the cell death after 3 h. Aminotriazole pretreatment enhanced the cell killing at 3 h but not at 1 h, and DPPD was not protective.
Catalase
added to the medium at 1 h inhibited the cell death measured at 3 h. In contrast, menadione killed hepatocytes pretreated with BCNU within 1 h. DPPD prevented cell death at 1 h, and there was evidence of lipid peroxidation in the accumulation of malondialdehyde in the culture medium.
Catalase
added with menadione did not prevent the cell killing at 1 h but did prevent it at 3 h. These data indicate that catalase and the GSH-GSSG cycle are active in the defense of hepatocytes against the toxicity of H2O2.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Endogenous defenses against the cytotoxicity of hydrogen peroxide in cultured rat hepatocytes. 396 66
This study investigated the effect (in vivo) of centrophenoxine (Helfergin) on the activity of antioxidant enzymes (glutathione peroxidase GSH-PER,
glutathione reductase
GSSG-RED, superoxide dismutase SOD and catalase) in subcellular fractions from the regions of the brain (cerebrum, cerebellum and brain stem) of rats aged 6, 9 and 12 months. In all age groups, normal (control) activity of GSH-PER, GSSG-RED and SOD in the three brain regions was higher in the soluble fractions than in the particulate fractions. The three regions of the brain showed different levels of the enzyme activities. Enzymes in soluble fractions (except GSSG-RED in cerebrum of rats aged 12 months) did not change with age. In particulate fractions, however, the enzymes showed age-related changes: GSH-PER decreased with age in cerebellum and brain stem, but showed an age-related increase in cerebrum, GSSG-RED and SOD increased with age in all the three brain regions.
Catalase
activity in all the three brain regions remained unchanged in all age groups. Six week administration of centrophenoxine (once a day in doses of 80 mg/Kg and 120 mg/Kg) to the experimental animals produced increases in the activity of SOD, GSH-PER and GSSG-RED in particulate fractions from all the three brain regions. In the soluble fractions, however, only SOD and GSH-PER activity was increased. In vitro also centrophenoxine stimulated the activity of GSH-PER. A dosage of 80 mg/Kg produced greater changes than a 120 mg/Kg dosage. The drug had no effect on the activity of catalase. Centrophenoxine also reduced lipofuscin deposits (studied both biochemically and histochemically) thus indicating that the drug inhibited lipofuscin accumulation by elevating the activity of the antioxidant enzymes. The data suggest that alleviation of senescence by centrophenoxine may, at least, partly be due to activation by it of antioxidant enzymes.
...
PMID:Effect of centrophenoxine on the antioxidative enzymes in various regions of the aging rat brain. 641 80
Our previous studies have demonstrated a decreased glutathione feroxidase (GSH-Px) activity of erythrocytes and leucocytes from multiple sclerosis (MS) patients. In the present communication these activities were compared with the activities of associated enzymes (
glutathione reductase
(GSSG-RD), glucose-6-phosphate dehydrogenase (G-6-PD) and catalase). All enzymic activities were compared between MS patients, other neurologic patients (ON patients) and normal control individuals. Compared to data of ON patients and normal controls, in MS the ratio of GSHPx/GSSGRD in lympho- and granulocytes was significantly decreased (2 alpha less than or equal to 0.05) by 35% and 51%, respectively. The significant correlation between GSSG-RD and the GSH-Px activity (2 alpha less than or equal to 0.05, r = 0.501) found in control lymphocytes was not present in MS lymphocytes. However, the lymphocyte GSH-Px activities of controls as well as of MS correlated with the corresponding serum selenium levels (2 alpha less than or equal to 0.05, r = 0.594 and 2 alpha less than or equal to 0.01, r = 0.967, respectively). The G-6-PD activity was insignificantly increased by 41% in MS lymphocytes compared to normal control.
Catalase
activity was unchanged in lymphocytes but decreased 50% in MS granulocytes compared to normal control. No significant differences were found between MS and the ON group. The catalase activity of MS erythrocytes was increased by 63% (2 alpha less than or equal to 0.05) in comparison with both the normal control and ON data.
...
PMID:Glutathione peroxidase and reductase, glucose-6-phosphate dehydrogenase and catalase activities in multiple sclerosis. 669 53
The effects of dietary vitamin E and selenium on the oxidant defense system (glutathione peroxidase, catalase,
glutathione reductase
, reduced glutathione, and superoxide dismutase) were investigated in the chick. Two-week-old chicks were reared using a vitamin E-free, low-selenium, semipurified basal diet alone or supplemental with vitamin E (100 IU/kg) and/or selenium (.10 ppm). Whereas vitamin E sustained chick growth, survival, and protection from exudative diathesis (ED), it did not significantly affect the enzymatic components of the oxidant defense system. Dietary selenium promoted chick growth and protection against ED in the absence of vitamin E and sustained glutathione peroxidase activity in several tissues. The latter effect was associated with decreases in reduced glutathione concentrations observed in liver and blood.
Catalase
and superoxide dismutase activities were increased in liver and brain in selenium deficiency.
Glutathione reductase
activities in liver, kidney, lung, and brain were not affected by diet.
...
PMID:Influences of dietary vitamin E and selenium on the oxidant defense system of the chick. 732 95
Because alveolar macrophages generate and release reactive oxygen metabolites but also contain antioxidative enzymes, they have the potential of either damaging or protecting tissues. We investigated the relative role of the hydrogen peroxide (H2O2)-scavenging antioxidative enzymes in H2O2 disposal and cell protection using freshly isolated (5 h ex vivo) and overnight (24 h ex vivo) cultured human alveolar macrophages. Cell protection was assessed on the basis of maintenance of cellular high-energy phosphates, leakage of intact nucleotides into the extracellular medium, and appearance of the nucleotide catabolic products xanthine, hypoxanthine, and uric acid. To investigate the relative importance of catalase and the glutathione redox cycle, the experiments were conducted in cells pretreated with amino-triazole (ATZ) to inactivate catalase or with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) to inactivate
glutathione reductase
.
Catalase
, glutathione peroxidase, and
glutathione reductase
activities did not change significantly during overnight culture of the cells. Both freshly isolated and cultured cells consumed exogenous H2O2 mainly by the catalase-dependent pathway. When the cells were exposed to H2O2 (100 microM), catalase and the glutathione redox cycle equally participated in maintaining cellular high-energy nucleotides. However, when cultured cells were exposed to formylated peptide (FMLP) (10(-7) M), the glutathione redox cycle was responsible for the maintenance of high-energy nucleotides. Furthermore, in both exposures, the glutathione redox cycle was more important in maintaining cell membrane integrity and preventing nucleotide leakage from the cells. Immunocytochemical labeling showed that catalase was primarily localized in the peroxisomal compartment of these cells.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Catalase and glutathione reductase protection of human alveolar macrophages during oxidant exposure in vitro. 754 73
Hyperplastic nodular cirrhosis was induced in rats by long-term (6 month) i.p. administration of thioacetamide at doses of 2.66 mmol/kg body wt, three times per week. The survival rate of animals at the end of the treatment was 90%. To follow the temporal changes samples at 0, 7, 15, 30, 45, 60, 90, 150 and 180 days from rats during thioacetamide intoxication and from chronological controls were obtained. The cirrhogenic ability of this treatment was assessed on the basis of morphological changes: the development of macronodular cirrhosis and the appearance of fibrous septa of collagen through portal spaces. Parameters of liver injury and cholestasis were obtained by assaying the serum activities of isocitrate dehydrogenase and gamma-glutamyltransferase. Enzymes and metabolites related to glutathione redox systems, as well as other antioxidant enzymes, were tested.
Catalase
and glutathione peroxidase, the two enzymes involved in the elimination of peroxides, and
glutathione reductase
decreased significantly at the end of the 6 months of intoxication, while Cu-Zn and Mn superoxide dismutases increased progressively during the long-term thioacetamide treatment. Protein thiol levels profile showed a biphasic change increasing from the 7th day and were insensitive to the 30% depletion of intracellular glutathione (GSH). To study the relationship of the intracellular thiols on the mechanisms of cell proliferation and differentiation during the cirrhogenic process, DNA content was assayed by flow cytometry in isolated hepatocytes, and DNA ploidy and distribution between G0-G1, S and G2 + M phases were determined. Remarkable changes in relation to a sharp increase in diploid population from 7 to 180 days (24.5%-->85.5%), a pronounced decrease in polyploid populations (tetraploid+octoploid) in the same period (73.7%-->12.3%), and elevations in the populations in S phase (S1 + S2) were observed in thioacetamide-treated rats. The results obtained indicate that hepatocytes isolated from thioacetamide-treated rats showed a marked tendency to diploidy, an enhancement in DNA replication parallel to the hepatic content of protein sulphydryl groups and a significant decline in antioxidant enzyme activities. The increase in protein thiols was independent of GSH level and of the thiol redox state.
...
PMID:Relationship between antioxidant systems, intracellular thiols and DNA ploidy in liver of rats during experimental cirrhogenesis. 761 93
Antioxidative enzymes viz: glutathione peroxidase,
glutathione reductase
, catalase and aldehyde dehydrogenase were determined in the liver of rats treated with three industrial solvents viz: xylene, toluene and methyl alcohol both separately and in combination. Inhibited activity of glutathione peroxidase suggests reduction of hydroperoxides to corresponding alcohols. However, activity of
glutathione reductase
increased so as to maintain the glutathione (GSH) reserves.
Catalase
protected the rats by counteracting the superoxide radicals. However, inhibition of aldehyde dehydrogenase is attributed to the decreased availability of sulfahydryl groups. A trend to optimization of enzyme activities in the liver of co-treated rats suggests enhanced metabolism and excretion of xylene and toluene in the presence of methyl alcohol.
...
PMID:Antioxidative enzyme in the liver of rats after exposure to xylene, toluene and methyl alcohol separately and in combination. 761 43
<< Previous
1
2
3
4
5
6
7
8
9
10
Next >>