Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04179 (MnSOD)
 2,777 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increases in lipid peroxide in kidneys of rats treated with cisplatin were examined in relation to decreases in the activities of Cu,Zn-superoxide dismutase (Cu,Zn-SOD), Mn-SOD, glutathione peroxidase (GSHpx), glutathione S-transferase (GST) and catalase. The activities of catalase, GSHpx and GST in the kidney and the liver were significantly decreased after cisplatin administration. The decrease of GST activity in the kidney was 87.3%, this was the largest decrease among these enzymes in the tissues examined. Cu,Zn-SOD activity significantly decreased only in the kidney. In contrast, the activities of these enzymes in the heart and the lung, which showed no increase in lipid peroxide in our previous study, were not significantly decreased. Cisplatin does not directly increase lipid peroxidation in vitro; therefore, the increase of lipid peroxide in the kidneys of these rats treated with cisplatin can be attributed to a decrease in the activities of lipid peroxide-protecting enzymes.
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PMID:Effect of cisplatin on the activities of enzymes which protect against lipid peroxidation. 157 81

1. The activity of antioxidant defense enzymes (SOD, CAT, GSH-Px and GST) was analysed during the autumn and winter in the ground squirrel adapted to 30 degrees C and subsequently exposed to cold for 6 and 24 hr. 2. The liver CAT activity as well as the IBAT CAT and GSH-Px activities differed between animals adapted to 30 degrees C, studied in autumn, and those studied in winter. 3. MnSOD activity in the liver was increased in autumn but decreased in winter after 6 hr cold exposure reaching the control level 24 hr later. Cold exposure induced a decrease in CAT activity (except after 24 hr cold exposure in winter) and an increase in GSH-Px activity. Lower GST activity was found after 24 hr exposure to cold in winter. 4. The IBAT SOD activity decreased under the influence of cold during both seasons with a tendency to return to the control level only in winter. Cold exposure produced a decrease in GST in both seasons and CAT activity in autumn. GSH-Px activity was increased in winter only. 5. The results indicate a seasonal dependence of the activity of antioxidant defence enzymes in the ground squirrel. Seasonal influence was evidenced in animals exposed to cold as well.
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PMID:Seasonal dependence of the activity of antioxidant defence enzymes in the ground squirrel (Citellus citellus): the effect of cold. 161 72

HA-1 hamster fibroblasts receiving fresh media every 24 h were continuously passaged in progressively increasing O2 concentrations for 18 mo (designated O2R95). These cells were significantly more resistant than parental HA-1 to clonogenic inactivation mediated by 95% O2 without media replacement. The O2R95 cell line exhibited increases in the activities of catalase (CAT), Mn superoxide dismutase (MnSOD), Cu,Zn superoxide dismutase (Cu,Zn SOD), and glutathione peroxidase (GPx). O2R95 cells demonstrated uniformly distributed increased staining for CAT, MnSOD, Cu,Zn SOD, and GPx proteins, as determined by immunohistochemistry. Cellular resistance to and metabolism of 4-hydroxy-2-nonenal (4HNE), a toxic byproduct of lipid peroxidation implicated in mechanisms of O2 toxicity, was examined in HA-1 and O2R95 cell lines. O2R95 cells were significantly more resistant to 4HNE cytotoxicity, which was accompanied by a significant increase in 4HNE metabolism. O2R95 cells also demonstrated an increase in total glutathione (GSH) and glutathione S-transferase (GST) activity, an enzymatic system believed to be involved with 4HNE metabolism. Furthermore, homogenates from O2R95 cells consumed greater quantities of 4HNE in the presence of NADPH (but not NADH, NAD+, or NADP+), suggesting that an enzyme(s) utilizing NADPH contributes to 4HNE metabolism, resistance to 95% O2 and 4HNE as well as increased total GSH, antioxidant enzyme activities, and NADPH-dependent metabolism of 4HNE, persisted in O2R95 cells for 75 days of growth in 21% O2. These findings are compatible with the hypothesis that aldehydic byproducts of lipid peroxidation contribute to mechanisms of O2 toxicity and the selective pressure exerted by exposure of cells to hyperoxia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A stable O2-resistant cell line: role of lipid peroxidation byproducts in O2-mediated injury. 161 58

We examined the influence of dehydroepiandrosterone (DHEA), a beta-agonist, and exercise training on enzymes that detoxify toxic oxygen species. Feeding 0.4% DHEA decreased hepatic cytosolic (c) selenium-dependent glutathione peroxidase (GPX), (-26%, P less than 0.0001) and increased hepatic mitochondrial (m) Mn superoxide dismutase (SOD), (+38%, P less than 0.001). DHEA decreased myocardial c-GPX (-21%, P less than 0.05) when compared to a beta-agonist (beta A; L644969 Merck and Co.) fed at 5 ppm but neither differed from the Control (C). In contrast, the beta A increased hepatic m-GPX (+25%, P less than 0.05). In skeletal muscle, DHEA and beta A decreased muscle c-GPX by 20 and 12%, respectively (P less than 0.0009). DHEA increased both muscle (+20%, P less than 0.01) and myocardial (+20%, P less than 0.05) c-glutathione S-transferase (GST) over beta A (+20%, P less than 0.01) but neither was significantly different from C. Similar to DHEA, chronic training (Tr) (1 h/day, 5 days/week at 27 m/min, 15% grade on treadmill) decreased hepatic c-GPX (-16%, P less than 0.003). Tr elevates muscle c-GPX (+36%, P less than 0.05) in C. Tr increased myocardial c-GPX by 28% in the beta A-treated rats, whereas Tr decreased myocardial c-GPX by 22% in the C (P less than 0.05, interaction). One hour of acute exercise (Ex) (70% VO2 max relative work load) decreased hepatic homogenate catalase (-12%, P less than 0.02) and increased hepatic m-Mn SOD (+28%, P less than 0.03). Ex decreased myocardial c-GST (P less than 0.05) only in the DHEA-treated rats. DHEA and Tr may improve efficiency of oxygen utilization at the tissue level with lower antioxidant enzyme activity in liver and locally protective up-regulation in muscle. beta A stresses oxygen utilization systems and liver responds by up-regulation of antioxidant enzymes. The increase in myocardial c-GPX activity in the beta A-treated group may be a protective effect against indirect catecholamine-induced myocardial necrosis which results from free radical generation.
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PMID:Dehydroepiandrosterone and a beta-agonist, energy transducers, alter antioxidant enzyme systems: influence of chronic training and acute exercise in rats. 198 Apr 4

Brain trauma was induced in rats by impact of a steel bar on the head with a force such that damage (as measured by neurological scoring) was reversible in fourteen days. Systemic treatment (intraperitoneal injections) with free bovine copper superoxide dismutase or a liposomal form of the enzyme considerably shortened recovery time to less than half. Tests included cranial nerves--cornean and aural reflexes, and sensorial motricity functions--gripping reflexes, displacement reactions, recovery and flexion reflexes, equilibrium tests and spontaneous mobility. Normalisation of EEG recordings was also greatly accelerated in the case of treated animals. No changes of brain glutathione peroxidase, glutathione transferase or Mn superoxide dismutase in traumatized animals were observed. However a slight decrease in Cu-SOD occurs. Cerebral lipoperoxidation is increased in the traumatized animals compared with controls. This increase is reduced on treatment of the rats with liposomal SOD (or the free enzyme). Very small amounts of the exogenous SOD pass the brain barrier, the permeability of which is increased in traumatized animals. The enzyme is particularly concentrated in the cortex. Despite apparent total neurological recovery at 15 days for untreated traumatized animals, significant differences in EEG recordings, in percentage cerebral water content and in histological examination of brain tissue of these controls compared with treated animals were observed with a net improvement in the latter case. The results obtained with this model suggest that clinical treatment of coma states and brain traumas with liposomal superoxide dismutase may have certain advantages over orthodox treatments.
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PMID:Treatment of brain trauma with liposomal superoxide dismutase. 322 60

An H2O2-resistant variant (OC14) of the HA1 Chinese hamster fibroblast cell line, which demonstrates cross resistance to 95% O2 and a 2-fold increase in total glutathione content, was utilized to investigate mechanisms responsible for cellular resistance to H2O2- and O2-toxicity. OC14 and HA1 cells were pretreated with buthionine sulfoximine (BSO) to deplete total cellular glutathione. Following BSO pretreatment, cells were either placed in 250 microM BSO to maintain the glutathione depleted condition and challenged with 95% O2, or challenged with hydrogen peroxide in the absence of BSO. Total glutathione and the activities of CuZn superoxide dismutase, Mn superoxide dismutase, catalase, glutathione peroxidase, and glutathione transferase were evaluated immediately following the BSO pretreatment as well as following 39 to 42 hr of exposure to 250 microM BSO. BSO treatment did not cause significant decreases in any cellular antioxidant tested, except total glutathione. Glutathione depletion resulted in significant (P < 0.05) sensitization to O2-toxicity and H2O2-toxicity in both cell lines at every time point tested. However, glutathione depletion did not completely abolish the resistance to either O2- or H2O2-toxicity demonstrated by OC14 cells, relative to HA1 cells. Also, glutathione depletion did not effect the ability of OC14 cells to metabolize extracellular H2O2. These data indicate that glutathione dependent processes significantly contribute to cellular resistance to acute H2O2- and O2-toxicity, but are not the only determinants of resistance in cell lines. The contribution of aldehydes formed by lipid peroxidation in mechanisms involved with the sensitization to O2-toxicity in glutathione depleted cells was tested by measuring the lipid peroxidation byproduct, 4-hydroxy-2-nonenal (4HNE), bound in Schiff-base linkages or in its free form in cell homogenates at 49 hr of 95% O2-exposure. No significant increase in 4HNE was detected in glutathione depleted cells relative to glutathione competent cells, indicating that glutathione depletion does not sensitize these cells to O2-toxicity by altering the intracellular accumulation of free or Schiff-base bound 4HNE.
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PMID:Contribution of increased glutathione content to mechanisms of oxidative stress resistance in hydrogen peroxide resistant hamster fibroblasts. 759 39

Although the mechanisms responsible for chemically induced oxidative stress are under intense investigation, little is known about the effects of prooxidant chemicals on the expression of drug-metabolizing enzymes. We examined the effects of diquat (0.1 mmol/kg, ip) and ciprofibrate (0.025% w/w, diet), chemicals which induce oxidative stress via different biochemical mechanisms, on the steady-state messenger RNA (mRNA) levels of six cytochrome P450 enzymes, seven glutathione S-transferase (GST) isoenzymes, UDP-glucuronosyl transferase 1-06 (UGT1*06), gamma-glutamylcysteine synthetase (gamma GCS), NADP(H):quinone oxidoreductase (quinone reductase), Cu/Zn superoxide dismutase (SOD), catalase, and 18S ribosomal RNA in the livers of male Sprague-Dawley rats. Effects of chemical treatments on mRNA levels were compared to changes in catalytic activities for selected enzymes. Ciprofibrate treatment selectively decreased CYP1A2 mRNA expression, whereas both chemicals suppressed CYP3A2 mRNA expression. CYP4A1 mRNA expression and lauric acid hydroxylase activities were induced by ciprofibrate treatment, whereas diquat treatment moderately increased CYP4A1 mRNA levels without affecting lauric acid hydroxylase activities. The steady-state mRNA levels encoding constitutively expressed GST isozymes (Ya1, Ya2, Yb1, Yb2, and Yc1) were decreased by diquat exposure, and the mRNA encoding four of the five constitutively expressed GSTs (Ya1, Ya2, Yb1, and Yc1) were also decreased by ciprofibrate treatment. Nonconstitutively expressed or low constitutively expressed genes (CYP1A1, CYP2B1, CYP2B2, GST Yc2, GST Yf, and UGT1*06) were not induced by exposure to the prooxidants. Changes in isozyme-specific catalytic activities were more consistent with the observed changes in mRNA expression for the GSTs than for the P450s. Both treatments had inhibitory effects on hepatic GSH biosynthesis by decreasing gamma GCS large-subunit mRNA expression, gamma GCS catalytic activities, and hepatic GSH concentrations. Cu/Zn SOD and quinone reductase mRNA levels were increased after ciprofibrate exposure, whereas Cu/Zn SOD mRNA expression was decreased in the diquat-treated animals. The results of this study indicate that diquat and ciprofibrate can decrease the expression profile of a number of phase I, phase II, and antioxidant enzymes and inhibit GSH biosynthesis. These effects may involve the pretranslational loss of hepatic mRNAs, possibly due to accelerated production of reactive oxygen species.
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PMID:The effects of diquat and ciprofibrate on mRNA expression and catalytic activities of hepatic xenobiotic metabolizing and antioxidant enzymes in rat liver. 767 60

We describe expression of alpha, mu and pi class glutathione S-transferase (GST) and, CuZn- and Mn superoxide dismutase (SOD) in human synovium and cultured synovial fibroblasts. Immunohistochemical and immunoblotting studies showed synovium and cultured cells expressed pi GST and both isoforms of SOD. Cellular localisation was largely perinuclear. No expression of alpha or mu GST was detected even though polymerase chain reaction analysis showed 4/6 subjects had positive genotypes at the polymorphic, mu class GSTM1 locus. Incubation of cultured synovial fibroblasts with H2O2, IL-1 alpha and the cyclooxygenase and lipoxygenase inhibitor, Tenidap, did not induce expression of alpha, mu or pi GST though treatment with IL-1 alpha caused a marked increase in the expression of Mn SOD.
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PMID:Alpha, mu and pi class glutathione S-transferases in human synovium and cultured synovial fibroblasts: effects of interleukin-1 alpha, hydrogen peroxide and inhibition of eicosanoid synthesis. 824 85

In the kidney, ischaemia-reperfusion results in both hypoxic and oxidant cellular injury which is most marked in the tubules of cortex and outer medulla. These contrasting conditions may have opposite effects on the expression of enzymes that reduce or repair oxidant damage. To investigate this, the activities of CuZn and Mn superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST) were measured after 4 h and 3, 6, and 10 days of reperfusion following sham surgery or 45- or 90-min left renal artery occlusion. The right kidney served as internal control. Sham surgery had no effect on Mn SOD or GPx, but caused small (p < 0.05) reductions in CuZn SOD and GST activities. Forty-five minutes of ischaemia had no net effect on Mn SOD, increased GPx activity (maximum at 6 days, p < 0.01), and reduced CuZn SOD (nadir 3 days, p < 0.02) and GST (nadir 6 days, p < 0.02) activities. Ninety minutes of ischaemia again had no net effect on Mn SOD, prevented the induction of GPx, and further suppressed the activities of CuZn SOD and GST. The activity of the non-anti-oxidant enzyme lactate dehydrogenase was equal in left and right kidneys after 45 min of ischaemia, but different (p < 0.01) 10 days following 90-min injury, due to a combination of reduced activity in the ischaemic kidney and an increase of activity in the internal control. The immediate effect of ischaemia-reperfusion injury on the kidney is to reduce the activity of intracellular anti-oxidant enzymes in proportion to the severity of the ischaemic insult. Recovery or net induction of enzyme activity paralleled tubular regeneration. Protection resulting in acquired resistance to a second ischaemic event is unlikely to be due to induction of anti-oxidant enzymes if it occurs within 6 days.
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PMID:Differential effect of ischaemia-reperfusion injury on anti-oxidant enzyme activity in the rat kidney. 852 79

Free radical production and lipid peroxidation are potentially important mediators in testicular physiology and toxicology. The cytochrome P450 enzymes of the steroidogenic pathway are known to produce free radicals. The present study was conducted to elucidate in vivo the gonadotropin regulation of free radical-mediated lipid peroxidation and the antioxidative defense system in the rat testis. GnRH antagonist (Org 30276; 1 mg/kg BW) and testosterone [40-mm SILASTIC brand (Dow-Corning) capsules] treatments were used to suppress serum gonadotropin levels. As expected, serum LH decreased to a very low level, whereas serum FSH decreased only slightly. Testosterone treatment for 8 days decreased the levels of the peroxide-metabolizing enzymes, catalase, glutathione peroxidase (GSH-Px), and glutathione transferase (-44%, -24%, and -31%, respectively; P < 0.01 for all). These changes predominately reflect the interstitial tissue, in which catalase and GSH-Px activities were much higher than in the seminiferous tubules. Testicular CuZn or Mn superoxide dismutase activities, which were high in the seminiferous tubules, were not affected by gonadotropin suppression. The total peroxyl radical-trapping capacity of the testis, or its components, vitamin E and ubiquinol 9, were not affected either. Lipid peroxidation was decreased after 8-day treatment, as detected by diminished formation of conjugated dienes and fluorescent chromolipids (-30% and -19%, respectively; P < 0.05 for both). Similar results of decreasing catalase and GSH-Px activities were found after gonadotropin suppression with GnRH antagonist treatment for 2 days or testosterone treatment for 5 days. Substitution with hCG, alone or in combination with recombinant human FSH, reversed the changes in enzyme activities, whereas FSH alone had no effect. After 5-day testosterone treatment, catalase messenger RNA expression was studied by Northern hybridization, and it was observed to parallel the changes in enzyme activity. The site of free radical production was studied by separating interstitial tissue and seminiferous tubules 5 h after hCG injection. GSH-Px was induced by hCG only in the interstitial tissue (+28%; P< 0.01), supporting the hypothesis of free radical production during steroidogenesis. Aminoglutethimide, an inhibitor of the P450 cholesterol side-chain cleavage enzyme, induced extensive lipid peroxidation in the testis. Presumably, aminoglutethimide leads to leakage of free radicals from the P450 enzyme when substrate oxygenation is prevented. In conclusion, the present study suggests that physiological LH action in the rat testis causes lipid peroxidation and maintains high activities of peroxide-metabolizing enzymes in the interstitial tissue.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Induction of lipid peroxidation during steroidogenesis in the rat testis. 853


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