[GnRH test in disorders of testicular function. Studies of the methodology and value in normogonadotropic...

In 42 men suffering from normogonadotropic oligospermia, the response of follicle-stimulating hormone (FSH) to 50 micrograms of intravenously administered gonadotropin-releasing hormone (GnRH) was determined after 15, 30, 60, 90 and 120 minutes. In most patients, the release of FSH rapidly increased during the first 30 minutes following GnRH administration, and there was little change after the maximum level of FSH (FSH max) had been achieved. FSH max was noticed after 30 minutes in 45,2% and after 60 or 90 minutes in other 45.3% of the patients; so every GnRH test should include the determination after 60 minutes. Hypergonadotropic response in GnRH test at normal basal levels of FSH may be diagnosed at sperm densities below 5 mill./ml. We regard a difference between basal and maximum level of FSH of more than 3 mU/ml to be a hypergonadotropic response. The GnRH test should not be confined to hypogonadotropic oligospermia; it may also be applied in endocrinological investigation of severe normogonadotropic oligo- and azoospermia.