The in vitro effects of lipid peroxidation on the content of individual forms of cytochrome P-450 in liver microsomes of guinea-pigs.

The effect of lipid peroxidation in vitro on the amounts of several forms of cytochrome P-450 in liver microsomes from guinea-pigs was investigated. Lipid peroxide formation in liver microsomes from ascorbic acid (VC)-deficient animals was much higher than that observed in control animals. The antibodies to rat P-450IA2 (P-448-H), P-450IIB1 (P-450b) and human P-450IIIA4 (P-450NF) recognized one or two forms of cytochrome P-450 in liver microsomes of guinea-pigs. Neither cytochrome P-450 cross-reactive with anti-P-450IIB1 antibodies nor cytochrome P-450 cross-reactive with antibodies to P-450IIIA4 was virtually affected by microsomal lipid peroxidation induced by NADPH in vitro. In contrast, the forms of cytochrome P-450 immunochemically related to P-450IA2 were decreased with the increased level of lipid peroxide formation. The form-specific degradation of cytochrome P-450 due to lipid peroxidation was in agreement with our previous observation that the amounts of cytochrome P-450 cross-reactive with antibodies to P-450IA2 but not with antibodies to P-450IIIA (P-450PB-1) were predominantly decreased in VC-deficient guinea-pigs compared to control animals in vitro.