Effect of sex hormones on the tissue localization of nuclear estrogen receptor positively stained cells in the seminal vesicle of immature castrated rats

We studied the changes in the tissue localization of nuclear estrogen receptor (ER) positively stained cells in the seminal vesicle of immature castrated rats under various environmental conditions of sex hormones by immunohistochemical methods. Ln castrated rats of 6 weeks of age, the percentage of nuclear ER positively stained cells showed remarkable increase in the periglandular stroma region, but not in the epithelium and the peripheral stroma region. Estrogen administration to castrated rats dramatically increased the percentage of nuclear ER positively stained cells in both the epithelium and the peripheral stroma region, whereas cessation of estrogen treatment caused a significant percentile decrease. These results suggest that the nuclear ER expression in both the epithelial cells and the peripheral stromal cells seems to respond to estrogen. The concomitant treatment of estradiol-17 beta (E2) with 5 alpha-dihydrotestosterone (DHT) completely inhibited these E2 mediated ER expression in the epithelium and the stroma. This result suggests that ER works only when E2 is given in the absence of DHT in the seminal vesicle of immature castrated rats.