Regulation of gonadotropin response in testicular feminization syndrome

The effects of hormonal manipulation on gonadotropin, androgen, and estrogen concentrations in a patient with testicular feminization syndrome (TFS) were studied to clarify the feedback regulation of gonadotropins. Baseline serum LH concentrations were normal to high and FSH concentrations were normal despite markedly elevated plasma testosterone concentrations, implying the lack of a reciprocal control relationship, and fluoxymesterone administration failed to alter gonadotropin or androgenic steroid levels. Clomiphene administration resulted in a rise in both LH and androgen levels, while moderate doses of exogenous estrogens effected a diminution in testosterone but did not significantly alter the levels of gonadotropins. Following gonadectomy, these same doses of estrogens produced a dramatic fall in the very high postoperative levels of gonadotropins. These results suggest that gonadotropin regulation is mediated by estrogens and not directly by androgens in TFS.