Acetylsalicylic acid--inducer of cytochrome P-450 2E1?

Pretreatment of rats with acetylsalicylic acid or sodium salicylate stimulates the metabolism of dichloromethane to carbon monoxide as measured by the carboxyhemoglobin level in blood. Simultaneous administration of dichloromethane and acetylsalicylic acid or sodium salicylate, respectively, was accompanied by reduced carboxyhemoglobin formation. In liver microsomes of rats pretreated with acetylsalicylic acid the p-nitrophenol hydroxylase activity was increased. It is concluded that (i) cytochrome P-450 2E1 is involved in the metabolic conversion of both dichloromethane and salicylic acid, and (ii) salicylic acid may be an inducer of cytochrome P-450 2E1.