Effect of di(2-ethylhexyl)phthalate (DEHP) on hepatic mixed function oxidases in different animal species.

Administration of 2000 mg/kg of di(2-ethylhexyl)phthalate (DEHP) for a period of 7 or 15 days in rats, mice, guinea pigs and rabbits produced a differential effect as judged by alterations in body weight gain, liver weight and activities of mixed function oxidases. DEHP exposure for 7 days caused an increase in the activity of aniline hydroxylase, arylhydrocarbon hydroxylase and ethylmorphine N-demethylase in rats, mice and guinea pigs, but a decrease in that of rabbits. However, exposure for 15 days produced a smaller degree of increase in the activity of these enzymes in rats and mice and even produced a decrease in the activity of these enzymes in guinea pigs. This differential response of DEHP in various animal species suggests a species difference in the toxicity of the plasticizer.