[Studies on the influence of piprozoline on the microsomal enzyme system of the rat liver (author's transl)].

Studies of hexobarbital sleeping time in rats showed that only a very high dosage of ethyl(Z)-(3-ethyl-4-oxo-5-piperidino-thiazolidin-2-ylidene)-acetate (piprozoline, Gö 919, Problin) (500 mg/kg) produced a weak interaction with the metabolism of hexobarbital; no signs of any induction of the oxidative enzyme system were observed until 4 days after pre-treatment with 3 X 250 mg/kg. Determinations of the in vitro activity of hepatic microsomal enzymes after several days pre-treatment of male Wistar rats with 2 X 250 mg piprozoline/kg per day showed that piprozoline has only a slight inductive effect on some of the enzymes of the oxidative system. Some of the glucuronidation reactions tested showed marked increases.