Distribution and concentrations of androgens in epithelial and stromal compartments of the human benign hypertrophic prostate.

Prostate tissues removed from patients with benign prostatic hypertrophy were separated into epithelia and stromal components and the concentrations of testosterone, 5 alpha-dihydrotestosterone, 5 alpha-androstane-3 alpha,17 beta-diol, 4-androstene-3,17-dione, 5 alpha-androstanedione and androsterone in these two fractions were determined by radioimmunoassays after the purification of solvent steroid extracts by Lipidex-5000 column chromatography. On a 'per cell' basis (i.e. relative to DNA), testosterone was equally distributed between the two components, while the other androgens measured were more abundant in the stroma. The observation that 5 alpha-reduced androgens (especially 5 alpha-dihydrotestosterone) were more concentrated in the stroma, and that significant correlations between concentrations of metabolically related androgens were more common in the stroma than in the epithelium, indicate that the stroma is an important site of androgen metabolism in benign prostatic hypertrophic tissues. The present data also support the suggestion that 5 alpha-dihydrotestosterone produced in the prostatic stroma may be transferred to the epithelium by way of sex hormone binding globulin in the extracellular spaces of the prostate.