Dosage des substances inhibant et stimulant la fixation de la FSH à ses récepteurs

Abstract

We describe a method to estimate binding of human ¹²⁵I-FSH to a preparation of bovine testicular receptors. Various experimental conditions are tested and the validity of the method is demonstrated. Using this method, the presence of biological substances modifying the FSH binding is measured in various fractions of ram rete testis fluid submitted to several steps of purification by chromatography. FSH receptor binding inhibitor (FSHRBI) activity is obtained in a low molecular weight fraction and FSH receptor binding stimulator activity in a larger one. These cybernin activities are isolated in fractions different from the ones observed with inhibin and GnRH like activities.