ABSTRACT
Introduction: Inhibition of pituitary gonadotropin secretion in men by testosterone (T) is principally mediated by aromatization to estrogen (E), which inhibits hypothalamic secretion of gonadotropin-releasing hormone (GnRH). Material and Methods: Longitudinal clinical investigation unit-based evaluation of the clinical and biochemical response to E-receptor blockade. Initial monotherapy with 50 mg of clomiphene citrate (CC) daily for a period of 9 months, with diurnal morning peak testosterone and luteinizing hormone (LH) levels evaluated at three-month intervals thereafter. Th e patient then resumed hormone replacement therapy (HRT) using T cream with adjuvant CC therapy. Main Outcome Measures were Baseline and stimulated T and LH levels; eff ect on sexual function. Result(S): CC therapy resulted in complete normalization of pulsatile gonadotropin secretion, serum T level, and sexual function. Conclusion(S): Isolated hypogonadotropic hypogonadism (IHH) may result from an acquired defect of enhanced hypothalamic sensitivity to E-mediated negative feedback. Whereas direct T replacement therapy can further suppress endogenous gonadotropin secretion, treating IHH men with gonadotropins can stimulate endogenous T secretion and enhance fertility potential. Reversal of gonadotropin defi ciency with CC was found to have a similar biological eff ect.