Inducibility of the hepatic drug-metabolizing capacity of mice infected with Schistosoma mansoni.

The activities of some hepatic microsomal drug metabolizing enzymes, which are markedly depressed in mice infected with Schistosoma mansoni, can be increased by treatment with phenobarbital or 3-methylcholanthrene. Administration of these compounds to infected mice increased the capacity of the liver to metabolize drugs up to the maximum level inducible in non-infected animals. However, the increased hepatic microsomal mass, reflected in glucose 6-phosphatase activities and cytochrome b5 levels, observed in schistosome-infected mice, was not increased further by the same treatment. The changes in the activities of several drug metabolizing enzymes in vitro were confirmed in vivo by determination of hexobarbital-induced sleeping time and zoxazolamine-induced paralysis duration.