A filter disc assay for the measurement and characterization of androgen-binding protein in unconcentrated media from Sertoli cell-enriched cultures.

As easy, rapid and sensitive assay which permits measurements of androgen binding protein (ABP) in unconcentrated spent media from Sertoli cell cultures is described. The method is based on the adsorption of the 5 alpha-dihydrotestosterone-ABP complex onto DEAE-cellulose filter paper discs at pH 8.5. It is demonstrated that this method permits the characterisation of ABP (ligand specificity, kinetic properties) and represents a useful tool for the study of the effects of various hormones on ABP production by cultured Sertoli cells. When added on day 5 of culture, FSH and other agents that raise intracellular cAMP increase ABP secretion up to 3 times. Natural and synthetic androgens provoke a 1.5-1.8-fold increase. The effects of androgens and FSH are additive and cyproterone acetate blocks the effects of androgens in the presence as well as in the absence of FSH.