Comparison of cumene hydroperoxide- and NADPH/Fe3+/ADP-induced lipid peroxidation in heart and liver submitochondrial particles. Mechanisms of protection by succinate.

The NADPH/Fe3+ /ADP system stimulates lipid peroxidation both in rat liver and bovine heart submitochondrial particles, while cumene hydroperoxide is active only in rat liver submitochondrial particles. The lack of a peroxidizing effect of cumene hydroperoxide in heart submitochondrial particles was related to the absence of cytochrome P-450. When ubiquinones are extracted from rat liver and bovine heart submitochondrial particles, succinate can still partially protect the cumene hydroperoxide-induced lipid peroxidation but not the peroxidation induced by NADPH/Fe3+ /ADP. The protective effect of succinate in lipid peroxidation was referred either to the reduction of ubiquinones that can act as antioxidants in the NADPH/Fe3+ /ADP system, or to the reduction of cytochrome P-450 that acts as a peroxidase in the cumene hydroperoxide system.