Dose-dependent effects of vinyltoluene inhalation on non-protein thiols and drug biotransformation in liver and kidneys of the rat.

1. Male Wistar rats were exposed to atmospheres of 50, 100 or 300 p.p.m vinyltoluene 6h/day, 5 days/week, for one or two weeks. 2. Hepatic non-protein sulphydryl content decreased in a dose-dependent manner when measured 0.5 h after the last exposure, both after one and two weeks. 3. The content of hepatic non-protein sulphydryl groups progressively increased 20 h after stopping the vinyltoluene exposure. 4. The activity of 7-ethoxycoumarin O-deethylase showed a dose-dependent increase both in liver and kidneys. The activity of UDP-glucuronosyltransferase also increased in a dose-related manner in both organs studied.