[An endometrium morphometry study on ovariectomized rats subjected to nilestriol and estradiol replalcement therapies].

This study was designed to evaluate the effect of estrogen on rat endometrium and compare the results of Nilestriol and Estradiol replacement therapies for preventing osteoporosis in ovariectomized rats. Forty 4-month old SD female rats were randomly divided into four groups, namely sham operation, bilateral ovariectomy, ovariectomy plus supplementary ethinyl estradiol (0.2 microgram/100 g B. W. qd x 5), and ovariectomy plus supplementary Nilestriol (0.15 mg/100 g B. W. once a week). Computerized image analyzer was used to evaluate the endomitrial pathological changes 10 weeks later. The results showed an atrophied endometrium in ovariectomized group, a slightly proliferative endometrium in Nilestriol treated group, and a markedly proliferative endometrium with local atypical hyperplasia in estradiol treated group. The difference between group 3 and group 4 in morphometry was significant (P < 0.5). These suggest the relative safety of Nilestriol replacement therapy for preventing menopausal osteoporosis.