Distribution of Infused Estrone in Human Plasma

Abstract

Intravenous infusions of 100 mg of estrone sulfate and of crystalline estrone were administered to adult male volunteers. Phlebotomy followed 2 hours after estrogen administration, 500 ml of whole blood being collected in each instance through a cationic exchange resin (Dowex-50). The plasma from each volunteer was fractionated immediately using Cohn's cold ethanol methods 6 and 9. The fractions obtained were I, III-0, II+IIIw, IV-1, IV-4, V and VI. Specific techniques were employed for the separation of the ß-lipoproteins and the albumin from fractions III-0 and IV-1. Estrogenic activity was assayed biologically in spayed rats by a modification of the method of Bulbring and Burn. Following the injection both of estrone sulfate and of crystalline estrone, the estrogenic activity was found associated with both the albumin and the α-globulins of the plasma. Fraction VI (albumin supernatant) exhibited activity in all experiments, due probably to the presence of unbound estrogens.