Abstract

In a study in which male rats have been exposed to 0, 20, 60, 200, 600 and 2000 mg di(isodecyl)phthalate (DIDP)kg diet for 2 weeks, body weight and liver weight and a number of enzyme parameters (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 which are related with peroxisome proliferation. No effects have been observed on liver and body weight. CAT appeared to be the most sensitive parameter with a dose-without-effect (DWE) of 60 mg DIDP/kg diet, corresponding with 5.6 mg DIDP/kg b.w./day. The other enzyme parameters PCO, ECH and LAH showed no effect at 200 mg DIDP/kg diet, corresponding with 18.4 mg/kg b.w/day. Since CAT is considered to be not specific for peroxisome proliferation this latter value has been established as overall no-observed-effect-level.