Pituitary-testicular function in acromegalic and hypophysectomized patients

Serum testosterone, LH, and FSH before and after i.v. injection of LHRH were studied in ten acromegalic men and in twenty-one males after hypophysectomy. Controls were normal men matched according to age. Compared to the controls, basal FSH was slightly higher and basal LGH slightly lower in the untreated acromegalics. The differences were not statistically significant. Serum testosterone and the ratio between basal FSH and LH were significantly lower in the patients. Following hypophysectomy because of acromegaly, the values were essentially unchanged. Hypophysectomy because of a functionless chromophobe adenoma resulted in a significantly lower maximum value of LH but not of FSH after LHRH. The results show that hypogonadism in acromegaly might be a result of imbalance between LH and FSH. They furthermore demonstrate that testing the pituitary-testicular function with LHRH in patients with pituitary disorders seems to be of limited value.