[The effect of phenobarbital and amidopyrine on the rate of decomposition of isoforms of cytochrome P-450 in mouse liver microsomes].

Separation of microsomal proteins in gradient polyacrylamide gel gives 60 protein bands. The molecular mass range of 48-58 kDa corresponding to cytochrome isozymes contains 7 bands for intact mice and 8 bands for phenobarbital-induced mice. Phenobarbital treatment causes both the appearance of a new cytochrome P-450 isozyme with a molecular mass of 56 kDa and the increase in the content of three isozymes with molecular masses of 54, 52.5 and 50 kDa. The half-life time of cytochrome P-450 isozymes in the livers of intact and phenobarbital-induced mice differs from 15 to 42 hours. Phenobarbital induction results in the breakdown acceleration of the isozyme with a molecular mass of 52.5 kDa and the breakdown retardation of the isozyme with a molecular mass of 54 kDa. Aminopyrine injections to phenobarbital-pretreated mice result in the breakdown acceleration of the cytochrome P-450 isozyme with a molecular mass of 56 kDa.