The role of cytochrome c and mitochondrial catalase in hydroperoxide-induced heart mitochondrial lipid peroxidation.
The role of cytochrome c and catalase in hydroperoxide-induced lipid peroxidation of rat heart mitochondria was investigated. Mitoplasts were prepared from hearts of aminotriazole-treated rats which displayed both an 80-90% reduction in matrix catalase activity and rate of H2O2 consumption. Catalase-depleted mitochondria were more susceptible to H2O2-dependent lipid peroxidation and had similar extents of tert-butyl hydroperoxide (t-BuOOH)-induced lipid peroxidation compared with control mitochondria. The magnitude of lipid peroxidation induced by H2O2 was greater than that for t-BuOOH in catalase-depleted mitochondria, while t-BuOOH induced soybean phosphatidylcholine (PC) liposome lipid peroxidation to a greater extent than H2O2. The t-BuOOH- and H2O2-dependent mitochondrial lipid peroxidation was inhibited 50 and 7%, respectively, by cytochrome c3+ depletion of mitochondria. Similar relative sensitivities to t-BuOOH- and H2O2-dependent peroxidation occurred for cytochrome c(3+)-supplemented soybean PC liposomes. These data show a critical role for cytochrome c3+ in hydroperoxide-induced mitochondrial lipid peroxidation and demonstrate the importance of matrix catalase in protecting heart mitochondria from the toxicity of H2O2.
Department of Anesthesiology, University of Alabama, Birmingham 35233-6810.
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Bush
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Freeman
D000818:Animals; D002374:Catalase / Q000378:metabolism*; D003574:Cytochrome c Group / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008081:Liposomes; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010545:Peroxides / Q000494:pharmacology*; D010713:Phosphatidylcholines / Q000378:metabolism*; D051381:Rats; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D020122:tert-Butylhydroperoxide
D003574:Cytochrome c Group; D008081:Liposomes; D016877:Oxidants; D010545:Peroxides; D010713:Phosphatidylcholines; D017392:Thiobarbituric Acid Reactive Substances; D020122:tert-Butylhydroperoxide; D006861:Hydrogen Peroxide; D002374:Catalase