Male and Female Forms of Human Follicle-Stimulating Hormone in Serum*

Abstract

The electrophoretic migration rate of FSH in serum from healthy men and women and from castrated men and estrogen-treated men were compared. The FSH activity was measured with a RIA. The charge of FSH from healthy men and postmenopausal women and from castrated men was almost identical (pi ∼4.1) and the mean values were not significantly different. FSH from premenopausal women was less acidic (pi∼4.4) than and the migration rate significantly different from that of FSH from postmenopausal women and both normal and castrated men. No relationship between charge of FSH and day of the menstrual cycle was detected. The form of FSH in estrogen-treated patients with prostatic carcinoma was less acidic than in nontreated patients or normal men. After treatment of sera with neuraminidase, the charge of FSH was similar in sera from pre- and postmenopausal women and normal and castrated men. The charge of FSH in serum of a patient with an FSH-producing adenoma was abnormal before as well as after treatment with neuraminidase. It is concluded that 1) a sex hormone related pleomorphism of FSH exists in man, 2) the charge of FSH is similar in postmenopausal women, normal men, and castrated men whereas the FSH in premenopausal women is less acidic, 3) estrogens can induce secretion of less acidic forms of FSH, 4) inmen testicular steroids in physiological concentration do not induce any change in charge of FSH, 5) the differences in charge observed for normal FSH most likely reflect different contents of sialic acid, 6) a tumor-produced FSH differed from normal FSH not only with regard to sialic acid content, and 7) pronounced species differences exist with regard to sex hormone related pleomorphism of FSH.J Clin Endocrinol Metab55: 682, 1982)