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)

CI-924 (5'5'-[1,1'-biphenyl]-2,5-diylbis(oxy)]bis [2,2-dimethyl-pentanoic acid]), a lipid lowering agent, was previously shown to be hepatotumorigenic in male and female B6C3F1 mice but not in male and female albino Wistar rats. To determine if the difference between the species in tumorigenic response correlated with the extent of peroxisome proliferation or microsomal changes the effects of CI-924 on liver were characterized in rats and mice. CI-924 doses of 0, 25, 75, and 150 mg/kg were administered in the diet for 4 weeks to B6C3F1 mice and albino Wistar rats. Peroxisomal beta-oxidation activity was significantly increased in all groups at doses of 25 mg/kg or higher and was induced up to 25 times in male rats. Peroxisomal carnitine acyltransferase and acyl-CoA oxidase activities were also increased, with the greatest induction observed in male rats. Catalase activity quadrupled in rats and doubled in mice. Serum liver enzyme activities were unchanged with the exception of 5'nucleotidase which was elevated in mice and decreased in male, but not female, rats. Glutathione S-transferase decreased in the males of both species and glutathione peroxidase increased in the mice. Cytochrome P450 4A1 increased in both species at doses of 25 mg/kg or greater and correlated with increased lauric acid hydroxylation. The high degree of peroxisome proliferation in male rats was unexpected in light of the lack of tumorgenicity demonstrated in a previous 2-year study and these results indicate that early peroxisome proliferation alone is not always a good predictor of hepatocarcinogenicity.
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PMID:Peroxisome proliferation and microsomal enzyme induction by the hypolipidemic CI-924 in rats and mice: relationship to tumorgenicity. 852 24

Catalase is the major peroxisomal H2O2-detoxifying enzyme and is thought to be critical in maintaining low H2O2 levels within a cell. It has been proposed that increased H2O2 levels may be involved in oxidative DNA damage and tumor promotion induced by peroxisome proliferators and other xenobiotics. To develop a mouse model system to address this issue, we have generated transgenic mice that exhibit a three- to four-fold increase in liver catalase levels. The activities of fatty acyl coenzyme A (CoA) oxidase and lauric acid hydroxylase were unchanged in transgenic mice, demonstrating that elevated catalase levels did not alter the activity of these other peroxisome proliferator-induced enzymes that produce active oxygen. These mice should help elucidate the role of H2O2 in cellular events mediated by peroxisome proliferators and other xenobiotics.
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PMID:Increased liver-specific catalase activity in transgenic mice. 876 64