EFFECT OF THE SELECTIVE ESTROGEN-RECEPTOR MODULATOR RALOXIFENE ON EXPLANTED UTERINE GROWTH IN RATS

Raloxifene is a selective estrogen receptor modulator known to have antiestrogenic effects on uterine tissue. In this study, the effects of raloxifene on uterine explant growth were evaluated in rats. Rats were ovariectomized, implanted with an estradiol pellet, and an endometriosis-like state was artificially created by suturing uterine explants near mesenteric blood vessels. Approximately 21 days after explant surgery, rats with confirmed uterine explant growth were given raloxifene orally at doses of 0 or 10 mg/kg/day for 7 or 14 days. After 7 days of raloxifene treatment, explant weight and volume were significantly decreased. Fourteen days of raloxifene treatment, also caused a decrease in explant weight and volume, though not statistically significant. In addition, raloxifene treatment caused weight of the remaining uterine horn to decrease. Histological examination of the explants confirmed the presence of endometrial tissue similar to that seen in the uterus. In this study, raloxifene suppressed explanted uterine growth in a rat model designed to mimic human endometriosis. (C) 1995 Wiley-Liss, Inc.