Effect of estrogens on luteinizing hormone release in testicular feminization syndrome before and after gonadectomy

The effect of exogenous estrogens on luteinizing hormone release was studied in three siblings with complete testicular feminization syndrome. Two subjects, 21 and 20 years old, were postpubertal. The third, 15 years old, was in the early pubertal stage. An estrogen provocation test was performed in which 20 mg of conjugated estrogens were administered intravenously and serum follicle-stimulating hormone and luteinizing hormone levels were assessed every 12 hours for 96 hours under basal conditions, on day 5 of an eight-day treatment with 0.2 mg/day ethinyl estradiol orally, and on day 5 of a subsequent eight-day treatment with 0.2 mg/day ethinyl estradiol and 120 mg/day cyproterone acetate orally. The first two tests were repeated one month after gonadectomy. During pregonadectomy treatments there was an overall luteinizing hormone fall. After gonadectomy, the two postpubertal subjects exhibited luteinizing hormone surges during ethinyl estradiol treatment -in one as a single peak and in the other as multiple peaks. A positive feedback effect was not induced in the youngest patient either before or after gonadectomy as in normal prepubertal and early pubertal females. The data suggest that testosterone or some other testicular factor inhibits estrogen induced positive feedback for luteinizing hormone. This inhibition mechanism acts independently of the testosterone cytosol receptor.