Abstract

In a study in which male rats have been exposed to 0, 20, 60, 200, 600 and 2000 mg dibutylphthalate (DBP)/kg diet for 2 weeks, body weight and liver weight and a number of enzyme parameters which are related with peroxisome proliferation (palmitoyl coenzyme-A oxidase (PCO, enoyl coenzyme-A hydratase (ECH), carnitine acetyl transferase (CAT) and lauric acid hydroxylase (LAH) have been determined in liver homogenates. No effect has been observed on the body and liver weight. For PCO a dose-without-effect was determined of 600 mg BBP/kg diet. The three other enzymes, ECH, CAT and LAH were more sensitive with a dose-without-effect (DWE) of 200 mg BBP/kg diet. Therefore, an overall no-observed-effect-level of 200 mg BBP/kg diet was established in this experiment, corresponding with 19.9 mg BBP/kg b.w./day.