CHANGES IN STEROID-HORMONE METABOLISM IN RAT-LIVER MICROSOMES FOLLOWING ADMINISTRATION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXINE (TCDD)

Treatment of male and female rats with 4 .times. 20 .mu.g/kg of TCDD led to 2- to 3-fold increases in liver microsomal cytochrome P450 levels concomitantly with changes in liver microsomal metabolism of 4-androstene-3,17-dione, 5.alpha.-androstane-3.alpha.,17.beta.-diol and 4-pregnene-3,20-dione. The changes were most pronounced in female rats where some hydroxylase activities increased 3- to 5-fold. The observed effects following TCDD administration may be related to the endocrine symptoms sometimes seen in patients exposed to this synthesis product of the herbicide 2,4,5-T [a teratogen].