EVIDENCE FOR A STIMULATORY ROLE OF FOLLICLE-STIMULATING-HORMONE ON THE SPERMATOGONIAL POPULATION IN ADULT MALES

Objective: To evaluate the effects of treatment with FSH on seminal in dices and on the seminiferous epithelium of oligozoospermic subjects w ith normal FSH plasma levels. Design: Placebo-controlled, double-blind randomized study. Setting: Academic setting. Patient(s): Ninety subje cts with idiopathic oligozoospermia (sperm count of <10 x 10(6)/mL) an d normal plasma levels of FSH. Intervention(s): Three months of treatm ent with FSH (60 patients) or placebo (30 patients); bilateral testicu lar fine-needle aspiration. Main Outcome Measure(s): Seminal indices; testicular cytologic features; plasma levels of FSH, LPI, and testoste rone; and ultrasonographic testicular examination. Result(s): Accordin g to seminal indices, patients treated with FSH and placebo were class ified as nonresponders or as responders (as determined by at least a d oubling of sperm count). No placebo-treated patients responded to trea tment. Among FSH-treated patients, 20 responded to hormonal treatment and 40 did not. The results of pretreatment cytologic examination of t esticular specimens from patients who did not respond to FSH treatment were consistent with hypospermatogenesis associated with maturational disturbances at the spermatid level. In contrast, patients who respon ded to treatment with FSH had isolated hypospermatogenesis without mat urational disturbances. After FSH therapy, we detected an increase of spermatogonia and spermatocyte population in both the responder and no nresponder subjects. This increase was associated with an activation o f spermatogenic and spermiogenic processes and with a rise in ejaculat ed sperm concentration only when isolated hypospermatogenesis was pres ent (responder patients). Conclusion(s): The findings of this study de monstrate that FSH treatment increases the spermatogonial population i n men. This treatment may be appropriate for oligozoospermic subjects who have normal FSH plasma levels and a testicular evaluation characte rized by hypospermatogenesis without maturational disturbances. (C) 19 98 by American Society for Reproductive Medicine.