Hepatic p-nitrophenetole O-deethylation Activity in Mice depends on Diet Composition

The present study investigated effects of various commercial diets, of protein and of fat 1evels in semisynthetic diets, and of fiber content and type on hepatic O-deethylation of p-nitrophenetole in mice. A high fat content increased and a high fiber content decreased the hepatic p-nitrophenetole O-deethylation activity. The activity in mice kept on different commercial feedings differed significantly. The level of hepatic microsomal cytochrome P-450 activity affects the toxicity of many compounds. Thus, standardization of commercial feeds for experimental animals used in toxicological and pharmacological studies is needed to avoid the potential risk of misleading conclusions