Studies on liver microsomes of female rats fed purified diets varying in fat content and with and without propyl gallate

This work was undertaken to determine whether or not propyl gallate, added as a 0·3% (w/w) supplement to purified diets containing various types and amounts of fat, modifies the function of the hepatic microsomal mixed-function oxidase system. The criteria used included measurements of liver weight, liver to body-weight ratio and hepatic microsomal-protein level as well as analyses of specific components and functions, such as total microsomal cytochrome P-450 content, and the levels of activity of aniline hydroxylase, aminopyrine N-demethylase and NADPH-cytochrome c (P-450) reductase. In contrast to butylated hydroxytoluene, propyl gallate at a level of 0·3% in the diet did not alter the function of the mixed-function oxidase system, even when administered in a diet high in polyunsaturated fat, which has a permissive effect on the induction of hepatic cytochrome P-450 levels by phenobarbital and 3-methylcholanthrene.