Metabolic and peroxisome proliferation studies with di(2-ethylhexyl)phthalate in rats and monkeys.

Male Fischer 344 rats and cynomolgus monkeys were treated with various doses of di(2-ethylhexyl)phthalate (DEHP) for at least 21 days. There was metabolic, biochemical, and morphological evidence for peroxisomal proliferation in rats that consumed diets containing 1000 ppm DEHP and above. These diets were estimated to provide average daily doses of about 100 mg/kg of DEHP. In contrast, peroxisomal proliferation was not observed in monkeys that received up to 500 mg/kg/day of DEHP by gavage. The results of this study suggest that rats do not provide a good model for predicting the results of DEHP exposure on peroxisomal proliferation in higher primates.