The formation of 5alpha-androstane-3alpha, 17beta-diol by dog prostate.

The 3-keto reduction of (1.2-3H)dihydrotestosterone to 3alpha and 3beta-androstanediol has been assessed in homogenates of 31 dog prostates that varied in size from less than 1 to greater than 15 g. The formation of both androstanediols was demonstrable in microsomes and cytosol, and both NADH and NADPH were effective cofactors for the two reactions. The formation of 3beta-androstanediol per unit weight of prostate or per mg protein did not show a clear-cut relation with the size fo the gland, but 3alpha-androstanediol formation per mg microsomal protein increased as a linear function with size so that the rates were on an average 10-fold greater in prostates greater than 15 g than in those less than 5 g in weight.