| Objective In the present study, we established the rat model of postmenopausal osteoporosis (PMOP) by bilateral ovariectomy, and investigated the effects of estrogen prophylactic administration on bone and other organs in postmenopausal rats. Methods The SD rats were divided into sham operation (Sham) group, ovariectomized (OVX) group and β-estradiol-treated OVX (OVX/E2) group. Daily subcutaneous injection of β-estradiol and determination of body weight were initiated 10 days post-surgery. The rats were sacrificed at 61 days post-surgery. Bones and organs were collected and weighed, and the organ index was calculated. Tissue sections were prepared and subjected to HE staining. Results Histomorphological observation showed that osteoporosis was found in the femur and tibia of the OVX rats, showing trabecular bone cracked and had larger space and structure disorder. No noticeable symptoms of osteoporosis were observed in the OVX/E2 group. Compared with the Sham group, endometrial mucosal epithelium was obviously thickened, the number of uterine glands in the lamina propria of endometrium was increased, and the glandular cavity became larger in the OVX group. No obvious pathological changes were observed in the OVX/E2 group. The analysis of body weight and organ index in rats indicated that ovariectomized rats resulted in increased body weight, as well as increased organ index of liver, lung, kidney and spleen, in the early postoperative period. Estrogen prophylactic administration could decrease the change of organ index to certain extent. Conclusion The above results show that timely administration of certain dose of estrogen could prevent the occurrence of postmenopausal osteoporosis, which provides a reference for the prevention and treatment of postmenopausal osteoporosis. |