Hormonal effects of estrogen-protein conjugates on rat uterus.

Abstract

Estrone-17-(0-carboxymethyl)-oxime-bovine serum albumin (BSA) and estradiol-17-beta- succinyl-BSA conjugates are used to evoke estrogen antibodies but here were tested in ovariectomized rats iv for acute estrogenic properties such as stimulation of uterine weight protein and RNA synthesis. 3 weeks after ovariectomy showed significant increases in uterine wet weight (p<.01) within 4 hours if given 1 mcg estradiol or estrone or 100 mcg estradiol-BSA (p<.02). No dose of estrone-BSA was effective up to 1 mg (equivalent to 87 mcg estrone). Weights rose within 2 hours after estradiol-BSA but a 10% increase was evident only 8 hours after estrone-BSA. 24 hours after 10 mcg estradiol BSA iv uterine protein content increased 127% and RNA content 261%. Uterine protein synthesis in vitro (carbon-14 lysine uptake) increased 190%. 500 mcg estrone-BSA increased protein content 154% RNA content 287% and protein synthesis 195%. No tritiated uridine uptake into RNA was detectable in vitro after 6 hours incubation. The greater uterine stimulation after estradiol-BSA than estrone-BSA was probably due to release of free estradiol.