STUDIES ON PITUITARY GONADOTROPHINS IN HUMAN PLASMA

Abstract

ABSTRACT Plasma pools obtained from men and postmenopausal women were extracted by an ammonium acetate-ethanol procedure and assayed by four biological systems assumed to measure »total« gonadotrophic activity, follicle-stimulating or luteinizing hormone activity. The 2nd International Reference Preparation for Human Menopausal Gonadotrophin, NIH-FSH-S2 and NIH-LH-S3 were used as standards. All assays were valid with regard to the statistical tests performed. Postmenopausal plasma contained 17 times more total gonadotrophic activity, 15 times more FSH activity and 4–6 times more LH activity than male plasma. The FSH/LH ratio was 2–4 times higher in postmenopausal than in male plasma. When postmenopausal plasma was calculated in terms of male plasma, the biological dissimilarity of the two materials was also indicated by the indices of discrimination for combinations of assays, which were significantly different from unity for all groups measuring a relationship FSH/LH.