EFFECTS OF BETA-IONONE ON THE EXPRESSION OF CYTOCHROME P450S AND NADPH-CYTOCHROME P450 REDUCTASE IN SPRAGUE-DAWLEY RATS

We have recently reported that beta-ionone induces cytochrome P450 (P4 50) 2B1 in rats. Effects of beta-ionone on the expression of other P45 0 isozymes and NADPH-P450 reductase were further investigated in Sprag ue Dawley rats. Administration of beta-ionone subcutaneously 72 and 48 h before sacrificing the animals not only significantly induced the l iver microsomal activities of P450-associated enzymes and NADPH-P450 r eductase, but also clearly increased in the level of P450 1A1/2, P450 2C, and NADPH-P450 reductase proteins. The induction of P450 1A1/2 and 2C by beta-ionone was much greater in male than in female as measured by western immunoblotting. Reverse transcriptase-polymerase chain rea ctions showed that, in addition to P450 2B1 and 2B2 mRNAs, P450 1A2, 2 C6 and NADPH-P450 reductase mRNAs were increased when beta-ionone was administered. Our previous and present results indicated that beta-ion one may induce several P450s and NADPH-P450 reductase by the accumulat ion of their corresponding mRNAs. (C) 1998 Elsevier Science Ireland Lt d. All rights reserved.