Roles of catalase and cytochrome c in hydroperoxide-dependent lipid peroxidation and chemiluminescence in rat heart and kidney mitochondria.

摘要: Abstract A recent report (Radi et al., J. Biol. Chem. 266:22028–22034, 1991) showed that rat heart mitochondria contain catalase. The protective role of mitochondrial catalase was tested by exposing or kidney and mitoplasts to two oxidants (H2O2) tert-butyl hydroperoxide, t-BOOH), estimating lipid peroxidation (as thiobarbituric acid-reactive substances, TBARS) overall oxidative stress chemiluminescence). Additional controls included preparations from aminotriazole-treated (catalase-depleted) rats. Both increased TBARS in catalase-free similar extents over their respective (between 200 350%). In catalase-containing preparations, H2O2 only 40 96% controls. Similar qualitative results were obtained when measuring chemiluminescence. catalytic cytochrome c investigated either control cytochrome-c-depleted (catalase free) t-BOOH. Hydrogen-peroxide-dependent varied with concentrations, remaining close concentration decreased 66%, even though there no present. Tert-butyl hydroperoxide-dependent less affected 2.3-fold above under the same conditions, suggesting organic peroxides are more likely remain polar membrane environment being decomposed heme nonheme iron imbedded inner membrane. Chemiluminescence depletion. Comparing cytochrome-c-deficient mitochondria, chemiluminescence 1.7-fold 2.8-fold higher challenged t-BOOH H2O2, respectively.