Abstract |
The hepatic biochemical effects of four chlorinated oxygen containing environmental contaminants were determined. Two oral doses of 1/5 the LD50 of 2,4-dichlorophenoxyacetic acid, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol and 2,3,4,6-tetrachlorophenol were given 21 and 4 hours before sacrifice to adult female rats. Although 2,4,6-trichlorophenol is a carcinogen in lifetime rodent studies, no evidence was found for DNA damage in rat liver or the white cells of rat blood. Similiarly no compound related changes were found in serum alanine aminotransferase, hepatic glutathione or cytochrome P-450 content. A dose of 193 mg/kg/day (slightly over the published rat LD50) of 2,3,4,6-tetrachlorophenol increased 5-fold the activity of hepatic ornithine decarboxylase. As 2,4,6-trichlorophenol did not damage DNA or induce hepatic ornithine decarboxylase (a marker of carcinogenic promotion) in the study, no explanation is apparent why this molecule is a carcinogen in rodent lifetime exposures and structurally related congeners are not. (Copyright (c) 1988 Gordon and Breach, Science Publishers, Inc.) |