The relationship between NADPH-dependent lipid peroxidation and degradation of cytochrome P-450 in adrenal cortex mitochondria

The relationship between NADPH-dependent lipid peroxidation and the degradation of cytochrome P-450 has been studied in bovine adrenal cortex mitochondria. Malondialdehyde formation is accompanied by a corresponding decrease in total cytochrome P-450 content. Inhibitors of lipid peroxidation also prevent the loss of cytochrome P-450, further demonstrating a direct relationship between NADPH-dependent lipid peroxidation and degradation of P-450. To differentiate between cytochrome P-450(11)beta and P-450scc, steroid-induced difference spectra were used to evaluate P-450 degradation. These measurements provide the first evidence that both P-450's are degraded during NADPH-dependent lipid peroxidation with P-450(11)beta being much more susceptible to this process.