Abstract

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.