目的:评价来曲唑对SD大鼠促排卵作用及其对胎鼠可能的致畸影响。方法:58只清洁级SD雌性大鼠随机分为空白对照组、溶剂(CMC)对照组及来曲唑不同剂量组(0.26mg/kg、0.52mg/kg、0.78mg/kg),分别于动情前期灌胃相应试剂,次晚合笼,阴栓及阴道涂片阳性者为孕0d,观察孕鼠的摄食饮水等一般情况,定期测体质量,于孕20d剖腹取胎仔,记录黄体数、着床腺数、吸收胎数、活胎数、死胎数、胎鼠体质量、身长、尾长等参数;每孕鼠取一半存活胎鼠进行内脏形态学检查,另一半做骨骼形态学检查。结果:CMC对试验结果无影响。来曲唑各试验组均对大鼠有促排卵作用,但可引起部分孕鼠流产,其活胎数、着床腺数低于对照组;胎鼠的植入前和植入后死亡率均高于对照组;来曲唑0.26mg/kg、0.52mg/kg对胎鼠无致畸作用,来曲唑0.78mg/kg组胎鼠内脏畸形率高于对照组。结论:来曲唑可促进大鼠的卵泡发育,但增加胎鼠的植入前和植入后死亡率;在≥0.78mg/kg剂量时,可能增加胎鼠的内脏畸形率。 Objective: To evaluate the effect of letrozole on ovulation in SD rats and its possible teratogenic effects on fetal rats. Methods: Fifty-eight SD female rats were randomly divided into blank control group, vehicle control group and letrozole different dose groups (0.26mg / kg, 0.52mg / kg, 0.78mg / kg) Pre-gavage of the corresponding reagents, the next cage, vaginal suppository and vaginal smear positive for pregnancy 0d, observe the general situation of pregnant rats feeding water, regular body mass, fetus abdomen fetus fetus 20d, record the number of luteal The number of bed gland, the number of fetuses fetus, the number of live fetuses, the number of stillbirths, the body weight of fetus, body length and tail length. Fetal rats were sacrificed every second pregnancy for visceral morphological examination and the other half for bone morphological examination. Results: CMC had no effect on the test results. Letrozole test groups all had ovulation-promoting effect on rats, but some pregnant rats could cause miscarriage, the number of live fetus and implantation gland was lower than that of control group. The pre-implantation and post-implantation mortality of fetuses Higher than the control group; Letrozole 0.26mg / kg, 0.52mg / kg no teratogenic effect on fetal rats, letrozole 0.78mg / kg group of fetal rat visceral malformation rate was higher than the control group. Conclusion: Letrozole can promote the follicular development in rats, but increase the pre-implantation and post-implantation mortality rate of fetal rats. At the dose of 0.78 mg / kg, letrozole may increase the rate of visceral malformations.