Role of catalase in metabolism of hydrogen peroxide by the perfused rat heart.
Cardiac metabolism of H2O2 was studied by determining the concentration dependence for H2O2-stimulated release of GSSG, an indicator for flux through the glutathione peroxidase pathway, in perfused heart preparations. Treatment of rats with aminotriazole in vivo inhibited heart catalase by 83% and shifted the dose-response curve for GSSG release toward lower H2O2 concentrations. In aminotriazole-treated rats, 50 microM H2O2 elicited a maximal rate of GSSG release (about 5 nmol GSSG/min per g heart), whereas 200 microM H2O2 was necessary for obtaining a similar rate of GSSG release in control rat hearts. The results show that catalase, although present at low levels of activity in the heart compared to other organs, functions as a major route for detoxication of H2O2 in the myocardium.
D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism; D019803:Glutathione Disulfide; D006861:Hydrogen Peroxide / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D006861:Hydrogen Peroxide; D002374:Catalase; D005978:Glutathione; D019803:Glutathione Disulfide; D000640:Amitrole