MONOTROPIC INCREASE OF SERUM FSH CORRELATED WITH LOW SPERM COUNT IN YOUNG MEN WITH IDIOPATHIC OLIGOSPERMIA AND ASPERMIA

ABSTRACT A group of 17 virile men ages 18–36 with idiopathic oligospermia or idiopathic aspermia had a mean serum FSH concentration (30±5 se μg LER 907/100 ml, immunoassay) significantly higher (p <0.001) than that of 49 normal men of the same age span (10±1) or 3 men with cystic fibrosis (18±1), but significantly lower (p <0.001) than serum FSH in 11 men with the Klinefelter syndrome (114±8). Among the oligoaspermics there was an inverse correlation (p <0.01) between the sperm count and serum FSH concentration. There was no significant difference in mean serum testosterone or LH concentrations among idiopathic oligoaspermics, cystics and normals, but the Klinefelters showed decreased serum testosterone and increased LH. These data support previous suggestions that pituitary secretion of FSH in men, unlike that of LH, may be regulated by some product of the germinal epithelium rather than by testosterone alone.