[Resistance of different forms of rat liver cytochrome P-450 to influence destabilizing microsomal membranes].

The authors studied the effect of actions destabilizing the membrane of hepatic microsomes on the spectral properties of cytochrome P-450 (P-448) in rats--intact and those given phenobarbital (PB) or 3-methylcholantrene (MC). There was revealed a marked resistance of microsomes induced with PB and MC to the enzymatic and nonenzymatic peroxidation of polyunsaturated fatty acids of membrane phospholipids. There was a distinct difference in the sensitivity of cytochrome P-448 and cytochromes P-450 in rats--intact and those given PB--to desoxycholate-Na treatment in vitro. The results obtained pointed to structural changes of the microsomal membranes in the case of induction with PB and MC representing two different types of hepatic monooxygenases inductors.