Effects of estradiol administration on the follicular tissue of hypophysectomized hens

Effects of hypophysectomy and estradiol administration on the incidence of atresia and the structure of the ovarian follicles were examined in the hen. Administration of high doses (9 or 13 mg/hen) of estradiol resulted in a decrease in the number of atretic follicles. In the nonatretic follicles of the hypophysectomized and estradiol-treated hens, no structural changes were observed except for the increase in the number of lipid droplets in the cytoplasm of granulosa cells and theca interna cells. It is suggested that the decrease in estrogen content in the follicular tissues may be involved in the process of atresia.