[Androgen receptor and 5 alpha-reductase activity in the epithelium and the stroma of human benign prostatic hyperplasia].

An average of 20 X 10(6) nucleated cells were obtained from 1 g tissue of human benign prostatic hyperplasia by mechanical separation technique. Of these cells, 96.2% showed acid phosphatase activity and this was 10 times higher than the remaining stromal fraction on a protein base. The total activity of 5 alpha-reductase was 81 times higher in stroma than epithelium and the total activity of 3(beta)-oxidoreductase was 29 times higher in stroma. Androgen receptor amount measured in total tissue, epithelium and stroma were 100, 29 and 62 fmol R1881/mg DNA, respectively. These results suggest that androgen metabolism takes place mainly in the stroma of human BPH tissue, and that BPH is probably the disease of prostatic stroma.