Induction of hepatic microsomal enzymes by diuron, phenobenzuron, and metabolites in rats.

Microsomal liver enzymes are induced in rats which are fed a diet containing 1000 ppm of phenobenzuron, a phenylurea herbicide, for 7 days: All parameters measured are about 50% higher than control values. This increase is lower after 14 feeding days. Diuron and 3,4-dichloroaniline have a similar, although lower, effect than phenobenzuron. Two other metabolites have no action on microsomal enzymes. The transitory and weak inducing effect of these phenylureas is interesting when compared to other organochlorine pesticides.