Immunolocalization of glutathione-peroxidase and androgen receptors in the rat dorsolateral prostate.

The effects of testosterone (T) and 17 beta-estradiol (E2) on the dorsolateral prostate of castrated rats were investigated by histopathological and immunohistochemical procedures. A significant increase in the prostatic weight of the castrated rats occurred after treatment with testosterone alone, or in combination with E2. Histologically, glandular hypertrophy was observed and fibromuscular stromal proliferation was also seen in the rats receiving the combination treatment. Immunohistochemical localization of glutathione-peroxidase (GSH-PO), an enzyme which effectively reduces the lipid peroxides, was clearly detected in the glandular epithelial 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 receptors (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 prostate. It is concluded that immunohistochemical analysis is very useful in studying the effects of androgen treatment on the prostate.