Effects of nafenopin, diphenylhydantoin, phenobarbitone and some acetylenes on body composition: is there a relationship between decreased carcass lipid and increased liver size and induction of drug metabolizing enzymes?

Arch, J. R.; Green, A.; Cawthorne, M. A.

Administration of nafenopin, diphenylhydantoin, phenobarbitone or the acetylenes BRL 15268 and BRL 19001 in the diet or, in the case of phenobarbitone, in drinking water reduced the body-lipid content of genetically-obese (ob/ob) mice. These compounds also reduced food intake in ob/ob mice. However, dietary restriction had less effect on body-lipid content than did the compounds. Nafenopin, diphenylhydantoin and BRL 15268 reduced the body-lipid content of normal mice and had no effect on food intake. Each of the compounds that reduced body-lipid content increased the liver weight of normal and ob/ob mice. BRL 15268 and BRL 19001 increased the maximum activity of NADPH oxidase in liver. It is proposed that these reductions in body-lipid content result from the increased metabolic rate involved in enlarging the liver and maintaining its increased size.