Gonadotropin Response to Luteinizing Hormone-Releasing Hormone in Men with Germinal Aplasia

Abstract

The effect of LHRH administration on plasma FSH and LH concentrations was evaluated in 3 men with germinal aplasia and six normal men. Mean basal FSH and LH levels were significantly higher (p < 0.01) in patients with germinal aplasia than normals, however, the mean LH concentration in patients was at the upper limit of normal range. Rapid injection of LHRH resulted in an elevation of FSH and LH concentrations in both normals and patients. For LH, the increase for patients (5.5-fold) was larger (p < 0.01) than that for normal men (3.5-fold). Similarly, the rise in FSH for patients (1.0-fold) was greater (p < 0.01) than that for normals (0.5-fold).These data indicate that in men with germinal aplasia some degree of physiologic restraint of FSH secretion remains operative despite markedly increased basal FSH levels. The exaggerated increase in LH concentration following LHRH supports the concept that a small but compensated, Leydig cell failure coexists in patients with germ cell depletion.