Postmenopausal Plasma Research Articles

STUDIES ON PITUITARY GONADOTROPHINS IN HUMAN PLASMA

ABSTRACT Gonadotrophic activity was estimated in individual plasma samples of 46 male and female subjects of all ages. The plasma was extracted by means of an ammonium acetate-ethanol procedure and tested biologically by the mouse uterine weight assay. The values in postmenopausal plasma ranged from 10 to 46 milligram-equivalents of the 2nd International Reference Preparation for Human Menopausal Gonadotrophin per litre. Plasma of men and women in the reproductive years contained 0.6–3.0 and 0.5–2.4 milligram-equivalents of the 2nd IRP per litre. The results in female plasma were assembled according to the day of the menstrual cycle. Though there was no significant difference in the mean values between group A (days 1–9), B (days 10–19) and C (days 20–30), the highest value was observed on the 13th day of the cycle of a 37 years old woman.

ESTIMATION OF PITUITARY GONADOTROPINS IN HUMAN PLASMA.

A rapid and simple method for estimation of gonadotropic activity in human plasma is described. The chemical procedure involves precipitation of plasma proteins with 5 ml of absolute ethanol per ml of plasma. The precipitate is then extracted twice with 2 ml of 10% ammonium acetate in 70% ethanol per ml of plasma used. Gonadotropic activity is measured utilizing the mouse uterine weight assay. The mean yield of solid material is about 8 % of the plasma solids, and the mean recovery of gonadotropic activity is 87 %. The purification is such that 20 ml equivalent of plasma can be administered to the test animal without toxic effects. One pool of postmenopausal plasma studied contained 17.880 μg equivalent for the 2nd International Reference Preparation of Human Menopausal Gonadotrophins (2nd IRP) per liter of plasma. Pools obtained from male subjects contained 1.200 μg equivalent of the 2nd IRP per liter. Pools from young female subjects obtained at random during the menstrual cycle contained 1.310 μg equiv...

Distribution and partial purification of pituitary gonadotropins of human plasma.

SummaryThe location and approximate concentration of gonadotropic activity in various fractions of human postmenopausal plasma has been determined. The plasma was fractionated by means of the cold ethanol method VI of Cohn and was assayed in immature female rats by estimating ovarian growth and secretory activity. Although traces of activity were found in Fractions IV-1, IV-4 and V, the bulk of the gonadotropically-active material was located in Fraction II + III. Subfractionation of Fraction II + III by successive precipitations with zinc and 20% ethanol freed the gonadotropins from the majority of the contaminating proteins.