CYP1A2 and 2E1 expression in rat liver treated with combined inducers (3-methylcholanthrene and ethanol).

The effects of combined ethanol and 3-methylcholanthrene treatment on rat hepatic cytochrome CYP1A2 and CYP2E1 expression were evaluated. Such a treatment attempts to mimic the simultaneous consumption of ethanol and cigarette smoke. Treatments involving 3-methylcholanthrene and combined ethanol + 3-methylcholanthrene decreased both CYP2E1 expression at the mRNA level (0.6 and 0.4 fold versus controls, respectively) and protein level (0.6 and 0.9 fold versus controls, respectively), while dramatically increasing CYP1A2 expression. Furthermore, combined treatment provokes a synergistic induction of CYP1A2 expression as determined by its catalytic activity and protein content.