PT  - JOURNAL ARTICLE
AU  - R. M. Welch
AU  - W. Levin
AU  - A. H. Conney
TI  - INSECTICIDE INHIBITION AND STIMULATION OF STEROID HYDROXYLASES IN RAT LIVER
DP  - 1967 Jan 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 167--173
VI  - 155
IP  - 1
4099  - http://jpet.aspetjournals.org/content/155/1/167.short
4100  - http://jpet.aspetjournals.org/content/155/1/167.full
SO  - J Pharmacol Exp Ther1967 Jan 01; 155
AB  - The in vitro addition of organic phosphorothionate insecticides, such as parathion, malathion and chlorthion, or halogenated hydrocarbon insecticides, such as chlordane and DDT, inhibited the liver microsomal hydroxylation of testosterone. Treatment of rats with chlorthion for 10 days inhibited the liver microsomal hydroxylation of testosterone, estradiol-17β, progesterone and deoxycorticosterone, whereas chronic treatment of rats with chlordane or DDT stimulated the hydroxylation of these steroids. More detailed studies on the hydroxylation of testosterone in specific positions revealed that chlorthion had a more marked inhibitory effect on the 16α-hydroxylation than on the 6β-or 7α-hydroxylation reaction. Chronic treatment of rats with chlordane or DDT stimulated the 6β-, 7α-and 16α-hydroxylation of testosterone, but had a more marked stimulatory effect on the 16α- hydroxylation reaction. These results suggest that the liver microsomal enzyme system responsible for the 16α-hydroxylation of testosterone differs from the systems that 6β-and 7α-hydroxylate this steroid. © 1967 by The Williams & Wilkins Company