Age dependency of androgen and estrogen effects on incorporation of (³H)‐thymidine by rat prostates in organ culture

Organ culture of the rat ventral prostate has been evaluated as a model for studying the biological effects of androgen agonists, androgen antagonists, and estrogens. Explants were cultured for up to 8 days, and incorporation of (³H)‐thymidine and (³H)‐uridine by the explants was measured. Dihydrotestosterone (DHT) increased the incorporation of (³H)‐thymidine/μg DNA when compared with the untreated controls at 4 days, P < .05; and at 6 days, P < .01. Enhanced uptake in explants from 6 to 8‐week old rats also was observed with 10 nM estradiol (P < .05) and 10 nM cyproterone acetate (P < .02). DHT (10 nM) caused greater enhancement of uptake in explants from 3‐week‐old rats than in explants from 6‐ or 12‐week‐old rats. In contrast, estradiol (E₂) increased incorporation only in prostates from the 6‐week‐old rats. Since both DHT and E₃ can enhance (³H)‐thymidine uptake even though they are associated with strikingly different effects on prostate morphology, it suggests that their effects on (³H)‐thymidine incorporation are mediated by different cells.