Mivotilate (YH439, 150 mg/kg, p.o.) reduces CYP2E1-mediated NDMA demethylase activity in rats, but shows no obvious effect on NADPH-dependent P450 oxidoreductase activity. Mivotilate (75-300 mg/kg) rapidly decreases immunoreactive CYP2E1 protein. Mivotilate (150 mg/kg, p.o.) inhibits the transcription of CYP2E1 in rats.