Effect of Trantinterol on Cytochrome P450 Enzymes

To study the effect of trantinterol on cytochrome P450 (CYP450) in rat liver microsomes,rats were given single daily oral doses of trantinterol or saline for one week. Liver microsomes were prepared and the effects of treatment on the total CYP450 content and the activities of CYP1A2,CYP2D6,and CYP3A4 were determined. The latter employed phenacetin,debrisoquine and midazolam respectively as probe substrates. The results indicate that the level of total CYP450 and the activities of CYP1A2,CYP2D6,and CYP3A4 in rat liver microsomes were unchanged after treatment by trantinterol (P0.05). Chronic oral administration of trantinterol did not lead to the induction of the representative enzymes of the main drug metabolizing CYP450 subfamilies.