Insect juvenile hormones: Chemistry and action: Edited by Julius J. Menn and Morton Beroza. Academic Press,New York, 1972, $11.00

Heptachlor metabolism was determined in young male rats fed for 10 days diets containing 18% protein supplied either by gluten or casein. Rats on the casein diet were either pair-fed on an individual basis to the gluten-fed animals or they were fed ad lib. Saline, sodium phenobarbital (80 mg/kg) or diethylaminoethyl 2,2-diphenylvalerate HCl (SKF 525-A, 50 mg/kg) was administered ip to the animals before sacrifice. Weight gain, liver microsomal protein, and heptachlor metabolism (nmole of product/g liver/10 min), assayed in 9000g rat liver supernatants, were found to be significantly reduced in the gluten-fed animals. Animals pair-fed the casein diet had higher heptachlor epoxidase activity than those fed ad lib. Phenobarbital pretreatment significantly enhanced the metabolism of heptachlor in animals in all groups to varying magnitudes. Heptachlor epoxidase activity (units/g liver) was increased 11-fold in the gluten-fed animals, 6-fold in the pair-fed animals on casein diet, and 7-fold in the animals fed casein ad lib. Heptachlor metabolism was less inhibited by SKF 525-A in the rats fed gluten compared to the rats on casein diet, either pair-fed or ad lib. The degree of induction or inhibition of enzyme activity was not influenced by restriction of food intake (pair-fed vs ad lib). The results of these studies suggest an interaction of protein inadequacy with drug metabolism and its induction or inhibition.