PT - JOURNAL ARTICLE AU - Joan Booth AU - James R. Gillette TI - THE EFFECT OF ANABOLIC STEROIDS ON DRUG METABOLISM BY MICROSOMAL ENZYMES IN RAT LIVER DP - 1962 Sep 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 374--379 VI - 137 IP - 3 4099 - http://jpet.aspetjournals.org/content/137/3/374.short 4100 - http://jpet.aspetjournals.org/content/137/3/374.full SO - J Pharmacol Exp Ther1962 Sep 01; 137 AB - Steroids with little androgenic activity, such as 19-nortestosterone and 4-chloro-19-nortestosterone acetate (SKF 6611), as well as androgenic steroids such as testosterone propionate, methyltestosterone and androstenedione increased the activity of several enzymes in rat liver microsomes when given to adult female rats (20 mg/kg) on alternate days for 4 weeks. All of the steroids produced 2-to 3-fold increases in the activity of the enzyme systems that metabolize hexobarbital, demethylate monomethyl-4-aminoantipyrine and hydroxylate naphthalene, but only 19-nortestosterone, testosterone propionate and methyltestosterone, increased the activity of microsomal TPNH oxidase. Treatment of castrated male rats with testosterone propionate or 19-nortestosterone ( 2 mg/kg on alternate days for 10 days) increased the weight of levator ani muscle as well as the rate of metabolism of hexobarbital and demethylation of monomethyl-4-aminoantipyrine about 2-fold. Although 19-nortestosterone nearly doubled the weight of the seminal vesicles, testosterone propionate caused a 14-fold increase. These findings suggest that the increase in microsomal enzyme activity is more closely related to the anabolic activity than to the androgenic activity of the steroid.