Comparative C₁₉‐Radiosteroid Metabolism in Primary Monolayer Cultures of Epithelial Cells and Fibroblasts from Rat Ventral Prostate, Canine Prostate, and Rat Lung

Stromal‐epithelial cell interactions may be important for the regulation of normal and abnormal prostatic growth. While androgen transformation by rat ventral prostate and canine prostate has been investigated in vivo and in organ culture, little is known about metabolic pathways in cultures of epithelial cells and fibroblasts. Metabolism of radioisotope‐labeled 17β‐hydroxy C₁₉‐steroids was studied in primary cultures of highly‐enriched rat ventral prostate and canine prostate epithelial cells and fibroblasts isolated by selective attachment procedures. The fibroblasts contained little testosterone 5α‐reductase in contrast to high activity in epithelial cells. We found high levels of 5α‐androstane‐3α,17β‐diol (3α‐diol) dehydrogenase and the terminal 5α‐androstane‐3β,17β‐diol (3β‐diol) hydroxylases in both cell types; 3α‐diol was a more effective precursor of 5α‐dihydrotestosterone than was testosterone. For prostatic fibroblasts these pathways seem to be differentiated functions, since rat‐lung fibroblasts converted 3β‐diol to 5α‐dihydrotestosterone and 3α‐diol. We conclude that epithelial cells and fibroblasts make interactive contributions to prostatic androgen metabolism. 1982 American Society of Andrology