Influence of the plasticiser di-2-ethylhexyl-phthalate on drug metabolising enzymes in the liver of uraemic rats.

After bilateral or subtotal nephrectomy male rats were given intraperitoneal injections of the plasticiser di-2-ethylhexylphthalate (DEHP) at differing time intervals in doses that do not affect the liver of normal rats. 200mg DEHP/100g body weight had no influence on the parameters measured. After administering 7 x 200mg/100g body weight for 14 days, liver weight and in vitro activity of the mixed function oxidation system increased significantly. In addition, the hexobarbital sleeping time decreased, indicating a stimulation of the activity of drug metabolising enzymes in vivo. Similar results were obtained after the administration of 56 x 50mg DEHP/100g body weight for 19 weeks. It is concluded that uraemic rats are more susceptible to inducing effects, but that the DEHP toxicity is of little importance.