Endogenous androgen levels in epithelium and stroma of human benign prostatic hyperplasia and normal prostate.

5 alpha-Dihydrotestosterone (DHT) and 5 alpha-androstane-3 alpha, 18 beta-diol (3 alpha-diol) were extracted from epithelium and stroma of human benign prostatic hyperplasia (BPH) and of normal prostate and quantified by RIA. The main results were: (1) concerning the BPH, DHT is mainly located in the nuclear fraction of epithelium and stroma, whereas 3 alpha-diol was completely of extranuclear origin, (2) in the nuclei derived from BPH stroma the DHT content (7.1 +/- 0.88 pmol/mg DNA, mean +/- SEM [n = 14]) was significantly higher (P less than 0.01) than in the nuclei derived from BPH epithelium (3.8 +/- 0.38 pmol/mg DNA [n = 14]). The DHT content in the nuclear fraction derived from unseparated, i.e. whole tissue, was 5.6 +/- 0.60 pmol/mg DNA [n =14], (3) the biological significance of the overwhelming DHT accumulation in the stromal nuclei for the BPH tissue is reflected by a significant correlation between the DHT values in the nuclei from stroma and whole tissue (rs = 0.710, P less than 0.01) and (4) in four normal prostates the DHT content in the nuclear fraction of epithelium (1.3 +/- 0.37 pmol/mg DNA) and stroma (2.2 +/- 0.93 pmol/mg DNA) was significantly lower (P less than 0.01, each) compared with the respective BPH fraction. These data support earlier findings which indicate that the stroma of BPH is a preferential tissue for androgen metabolism.