Abstract
In a previous paper it was reported that the activities of drug-metabolizing enzymes of liver microsomes were markedly decreased in male and female rats bearing Walker 256 carcinosarcoma (1). It was often observed that the activities and in vivo metabolism of many drugs in rats under various conditions were related to the activities of drug-metabolizing enzymes of liver microsomes (2-10). For example, the activities of drug-metabolizing enzymes were markedly increased in the rats treated with the barbiturates, carcinogenic polycyclic hydrocarbons and anabolic hormones, in consequence the in vivo metabolisms of drug were markedly increased and the effects of various drugs were markedly decreased (3-6). The purpose of present studies is to investigate the effect and toxicity of drugs in rats bearing Walker carcinosarcoma 256 and the correlation among the alternations of the effect and toxicity of drugs, the in vivo metabolisms of drugs and the activities of drug-metabolizing enzyme systems of liver microsomes.
