Concentrations of unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol and 5 alpha-androstane-3 beta, 17 beta-diol and their precursor in human testicular tissue. Comparison with testosterone, 5 alpha-dihydrotestosterone, estradiol-17 beta, and with steroid concentrations in human epididymis.

The concentrations of testosterone and its tissular metabolites were determined in testicular and epididymal tissue obtained from eleven male subjects (aged 65-85 years) after orchiectomy for prostatic cancer. The steroids were measured in different tissular compartments, i.e. testis, caput, corpus and cauda epididymis. The values (mean +/- SD; ng/g wet weight) were: Testosterone 724.0 +/- 286.0, 32.08 +/- 2.56, 41.45 +/- 1.77 and 32.24 +/- 2.14; 5 alpha-dihydrotestosterone 6.95 +/- 1.99, 9.76 +/- 2.33, 16.87 +/- 0.21 and 15.79 +/- 2.67; 5 alpha-androstane-3 alpha, 17 beta-diol 6.07 +/- 2.33, 2.17 +/- 0.24, 1.93 +/- 0.02 and 1.17 +/- 0.20; 5 alpha-androstane-3 beta, 17 beta-diol 56.66 +/- 20.97, 3.55 +/- 0.19, 2.21 +/- 0.27 and 3.34 +/- 0.32; estradiol-17 beta 5.36 +/- 3.0, 1.08 +/- 0.014, 1.44 +/- 0.038 and 1.47 +/- 0.03, respectively. Incubation of human testicular tissue with [3H]androst-5-ene-3 beta, 17 beta-diol or [3H]dihydrotestosterone showed that both androstane-diols were exclusively formed from dihydrotestosterone. Since high concentrations of 5 alpha-androstane-3 beta, 17 beta-diol are found in testicular tissue it is suggested that this steroid may be an index of seminiferous tubular function.