Radio Receptor Assay Studies of 125I-Testosterone Binding to its Receptors in Benign and Malignant Human Uterine Tumors

Abstract

A Radio receptor assay procedure was developed for the determination oftestosterone receptors in two groups of human uterine tumor patients (b€nign and malignano. The optimum conditions of the bindiry ofrz5l-testosterone to the receptors were as follows: receptor concentration: (250 ug proteh), tracer tesiosterone concentration (0.9 ng per 100! ), time (8 fu), pH (8.0) and tempemtues (4 and 25"C) for benign and malignani tumors respectively. Incubation of u{abeled testosterone and estradiol with uterine tumor tissue homosenate inhibited the ability of ]'?sl-testosterone to binal the uterire tissue lomogenate, whiie Eogestede in-hibjted the binding slightly. The use of0.1 M ofsodiurn halides and 0.025 M of divalent salts wore shown lo cause differ€nt €ffects on the binding in the two groups