3-Alpha-androstanediol and prostatic growth: comparison of 3-alpha-androstanediol formation in prostates from 8 species including man and dog.

To determine whether the formation of 3-alpha-androstanediol is critical for androgen-mediated growth of the prostate the conversion of dihydrotestosterone to 3-alpha-androstanediol was assessed in homogenates of 60 normal prostates from 8 species. Rates (nmol. times gm. tissue(-1) times hour(-1)) in the presence of reduced nicotinamide adenine dinucleotide phosphate as cofactor were as follows: dog 271, mouse 200, rat 160, opossum 109, rabbit 24, guinea pig 13, man 11 and cat 9. There was no correlation between prostate size and 3-alpha-androstanediol formation in the entire group. Therefore, either differences in the response to 3-alpha-androstanediol within the prostate or variations in the metabolism of 3-alpha-androstanediol must be more important than the rate of its formation for the development of prostatic hypertrophy in the dog.