[Specific binding of [3H] 5 alpha-androstane-3 beta, 17 beta-diol by cytosol from male and female rat hypophysis].

Evidence for specific binding of [3H]5 alpha-androstane-3 beta, 17 beta-diol (3 beta-diol) in the cytosol of male and female rats was confirmed by determining the apparent dissociation constant and the number of binding sites calculated by the Scatchard method. Centrifugation of hypophysial cytosols in sucrose density gradient revealed the binding at 4.5 S and 8--8.5 S and specific binding of 3 beta-diol around 4.5 S. The presence of protein-bound radioactivity was shown by gel-filtration of Sephadex G-200. The specific binding of the protein was demonstrated in the region of bovine serum albumin elution. Data on the effect of some androgenes and estrogenes on the specific binding of 3 beta-diol by the cytosol of male and female rat hypophysis are presented.