[Changes in tryptophan pyrrolase activity in the rat liver after a single injection of the hepatocarcinogen 4-dimethylaminoazobenzene and its noncarcinogenic analog].

A single injection of hepatocarcinogen 4-dimethylaminoazobenzene in rats results in considerable changes of tryptophanpyrrolase of the liver. A non-carcinogenic analog 4-diethylaminoazobenzene causes similar, although a milder shift. The observed injury of definitive hepatocytes and proliferation of oval and transition cells, due to the toxic effect of both the agents, may be one of the causes of changes in tryptophan pyrrolase activity.