ORNITHINE DECARBOXYLASE ACTIVITY AND POLYAMINE LEVELS IN THE EPIDIDYMIS OF PREPUBERTAL RAT AFTER ANTIANDROGEN ADMINISTRATION

The antiandrogens flutamide and casodex have been administered subcuta neously (vehicle, 1, 5, or 10 mg per day) to prepubertal male rats for 10 days. A significant change of epididymal weight has been observed after both treatments, from the lowest dose used. Epididymal dihydrote stosterone concentrations were significantly increased in flutamide- o r casodex-treated rats, while epididymal 3 alpha-androstanediol concen trations were affected only after flutamide administration, suggesting a differential effect on androgen metabolism between both antiandroge ns. Omithine decarboxylase (ODC) activity was significantly decreased by flutamide, and to a lesser extent by casodex. Antiandrogen administ ration resulted in a significant decrease in epididymal content of the polyamines putrescine, spermidine, and spermine. A slight but signifi cant decrease in putrescine and spermidine concentrations, but not in spermine, was observed after flutamide treatment. However, casodex had no effects on polyamines levels. A decrease in putrescine concentrati on was detected only when ODC activity fell to rather low levels. Inte rference of the antiandrogens with the biological action of androgens on ODC activity was clearly seen in immature male rats. Therefore, bot h epididymal growth and differentiation, in correlation to ODC activit y, would be severely affected at an early period of sexual development , such as prepuberty.