Androgen metabolism in the epithelial and stromal components of the human hyperplastic prostate.

The reduced and oxidized metabolites of testosterone and dihydrotestosterone were measured in the stromal and epithelial components of 23 human hyperplastic prostates. Our studies indicate differences in the hormonal metabolic patterns of the stroma and epithelium of the resected specimens when compared with tissues obtained retropubically. Testosterone 5 alpha-reductase was evenly distributed between the two components of the specimens obtained retropubically whereas the 3 alpha (beta)-hydroxysteroid dehydrogenase was predominantly located in the stroma. The measurements on the resected specimens suggest, on the other hand, that the bulk of the 5 alpha reductase and 3 alpha (beta)-hydroxysteroid dehydrogenase activities were confined to the stroma although these activities were considerably lower than those measured in the corresponding components of the retropublically obtained specimens. The conversion of testosterone to androstenedione was negligible in all the samples analysed. We therefore conclude that the stroma is the main site for the transformation of dihydrotestosterone to the androstanediol epimers and that the asymmetric distribution of the 3 alpha (beta)-hydroxysteroid dehydrogenase may be instrumental in the development of hyperplasia in the prostate gland. Furthermore, the results of this study indicate that electroresection impairs the enzymatic activities of the tissue.