Androgen binding in the baboon prostate.
Androgen receptors were identified and partly characterized in cytosols of the caudal and cranial prostatic lobes of a 24-hr castrate baboon. Binding of cyproterone acetate (CA) to testosterone-binding globulin (TeBG) in baboon serum was negligible and therefore was an appropriate unlabeled competitor for distinguishing high-affinity binding of tritiated dihydrotestosterone (3H-DHT) to serum contaminants and receptors in cytosol preparations when multiple-point saturation analyses and removal of free steroid by charcoal adsorption were used. Specificity of androgen binding was demonstrated by the inability of diethylstilbestrol, a synthetic estrogen known to have low binding affinity for TeBG, to displace 3H-DHT from the receptor protein. The number of high-affinity binding sites and the dissociation constant of the androgen receptor calculated for the caudal lobe were 102 fmoles/mg cytosol protein and 4.0 X 10(-9) M, respectively; corresponding values for the cranial lobe were 49 fmoles and 1.3 X 10(-9) M.
D000818:Animals; D001667:Binding, Competitive; D003534:Cyproterone; D013196:Dihydrotestosterone; D000882:Haplorhini; D008297:Male; D010215:Papio; D011467:Prostate / Q000032:analysis*; D011944:Receptors, Androgen / Q000032:analysis*; D011987:Receptors, Steroid / Q000032:analysis*; D012738:Sex Hormone-Binding Globulin
D011944:Receptors, Androgen; D011987:Receptors, Steroid; D012738:Sex Hormone-Binding Globulin; D013196:Dihydrotestosterone; D003534:Cyproterone