%0 Journal Article %A Ryuichi Kato %A James R. Gillette %T EFFECT OF STARVATION ON NADPH-DEPENDENT ENZYMES IN LIVER MICROSOMES OF MALE AND FEMALE RATS %D 1965 %J Journal of Pharmacology and Experimental Therapeutics %P 279-284 %V 150 %N 2 %X Although liver microsomes from male rats metabolize most drugs more rapidly than do those from female rats, the magnitude of the sex difference varies markedly with the substrate. There is more than a 3-fold sex difference with substrates like aminopyrine and hexobarbital, but virtually no sex difference in the hydroxylation of aniline and zoxazolamine. The effects of starvation of male rats range from impairment of sex-dependent enzymes which metabolize aminopyrine and hexobarbital to enhancement of the sex-independent enzyme that hydroxylates aniline. In contrast, starvation of female rats increases the specific activity of the aminopyrine- and hexobarbital-metabolizing enzymes as well as aniline hydroxylase. Since the sex-dependent enzymes are impaired in fasted male rats but enhanced in fasted female rats, starvation diminishes if it does not abolish the sex difference in the metabolism of drugs by rat liver microsomes. Starvation does not alter the metabolism of hexobarbital and enhances the metabolism of aminopyrine by liver microsomes from castrated rats, but impairs the metabolism of these compounds by liver microsomes from castrated rats receiving methyltestosterone. The Williams & Wilkins Comapny %U https://jpet.aspetjournals.org/content/jpet/150/2/279.full.pdf