The effect of androgens and antiandrogens on the immunohistochemical localization of the androgen receptor in accessory reproductive organs of male rats.

The androgen receptor (AR) was localized immunohistochemically after different hormonal treatments in the ventral prostate, coagulating gland, seminal vesicle and epididymis of the adult rat. In the untreated controls AR-immunoreactivity was confined to the cell nuclei. One week after castration or treatment with the gonadotropin-releasing hormone antagonist Cetrorelix (150 micrograms/animal per day) a cytoplasmic staining occurred in the epithelial cells of the ventral prostate and in part of the coagulating gland and seminal vesicle. In contrast, the AR remained exclusively in the nuclei in the epididymal epithelium and the glandular smooth muscle layer even after 2 weeks of androgen depletion. Bolus injections of either dihydrotestosterone (1 mg/kg), the antiandrogen flutamide (40 mg/kg), or the novel non-steroidal antiandrogen casodex (40 mg/kg) to androgen-depleted animals eliminated cytoplasmic AR-immunoreactivity and restored the nuclear staining pattern in the ventral prostate. A sustained 2-week treatment with the antiandrogens resulted in a loss of weight in all organs but did not alter the distribution of AR-immunoreactivity. The data show an apparent cytoplasmic/nuclear ligand-dependent translocation of the AR in the ventral prostate, coagulating gland and seminal vesicle but not in the epididymis of the adult rat.