Abstract
The effects of testosterone and 17β-estradiol (E2) on the dorsolateral prostate of castrated rats were investigated by histopathological and immunohistochemical procedures. Male Sprage-Dawley rats were divided into four experimental groups. Group 1 consisted of intact controls. The other animals were castrated. In group 2, rats were sacrificed 2 days after castration. The castrated animals were treated for 6 weeks with 1) testosterone I mg/head (Group 3) and 2) testosterone I mg/head plus E2 10 μg/head (Group 4). A significant increase in the dorsolateral prostatic weight occurred after 6 weeks treatment with testosterone plus E2 (Group 4). Histopathologically, glandular hyperplasia with fibro-muscular stromal proliferation was clearly observed, and the number of bromo-deoxyuridine (BrdU)-positive cells showed a significant increase over that induced by testosterone alone. Immunohisto-chemical localization of glutathione peroxidase (GSH-PO) which effectively reduces the lipid peroxides, was clearly observed in the glandular epithelial cells of the dorsolateral prostate following testosterone alone or testosterone plus E2-treatment. Therefore, it appeared that GSH-PO protein synthesis in the glandular epithelium of the dorsolateral prostate can be enhanced (induced?) by sex hormones such as testosterone and E2. In the dorsolateral prostate of intact rats, positive staining for androgen receptor (AR) was observed in nuclei of the glandular epithelial cells. In addition, immunodetectable AR decreased within 2 days after castration, but returned to intact levels after administration of testosterone. These findings agree with previous work on the ventral prostate. Furthermore, in group 4, AR was also detected in the nuclei of the proliferated stromal fibro-muscular cells. It is concluded that immunohisto-chemical analysis, using GSH-PO and AR, may be a useful method for predication of the effects of androgen. action on the rat prostate.
