中文摘要：

目的研究毒死蜱对小鼠卵巢的生殖毒性及对相关凋亡基因表达水平的影响。方法将40只健康6周龄无生育史清洁级ICR雌性小鼠按体重随机分为4组，分别为阴性对照（玉米油）组和7．5、15．0、30．0mg／kg毒死蜱染毒组（采用灌胃方式染毒，染毒容量为10ml／kg，每天1次，每周连续染毒6d），每组10只。染毒时间为2周。统计各期卵泡构成和颗粒细胞凋亡情况，检测相关凋亡基因的表达水平。结果与阴性对照组比较，15．0、30．0mg／kg毒死蜱染毒组原始卵泡以及30．0mg／kg毒死蜱染毒组闭锁卵泡的构成比均较高，15．0、30．0mg／kg毒死蜱染毒组生长卵泡以及30．0mg／kg毒死蜱染毒组成熟卵泡的构成比均较低，差异均有统计学意义（P〈0．05）。且随着毒死蜱染毒剂量的升高，原始卵泡的构成比呈上升趋势，成熟卵泡的构成比呈下降趋势，生长卵泡的构成比呈先上升后下降的趋势，而闭锁卵泡的构成比呈先下降后上升的趋势。仅30．0mg／kg毒死蜱染毒组卵巢颗粒细胞凋亡指数显著增高，差异有统计学意义（P〈0．05）；且随着毒死蜱染毒剂量的升高，小鼠卵巢颗粒细胞凋亡指数呈上升趋势。15．0、30．0mg／kg毒死蜱染毒组小鼠卵巢组织中mch3mRNA的表达增高，bcl-2mRNA的表达下降，差异均有统计学意义（P〈I）．05）。且随着毒死蜱染毒剂量的升高，小鼠卵巢组织中mch3mRNA的表达呈上升趋势，bcl-2mRNA的表达呈下降趋势。结论毒死蜱具有雌性生殖毒性，通过上调mch3的表达和下调bcl-2基因的表达，促进颗粒细胞凋亡，诱导卵泡闭锁，引起卵巢损伤，造成小鼠生育力降低。

英文摘要：

Objective To observe the toxic effect of chlorpyrifos on the ovary of mice and the expression level of apoptotic genes in ovary of exposed mice. Methods Fifty ICR mice were randomly divided into five groups, 10 in each group,including a negative control group （corn oil）,a positive control group （estradiol） and three experimental groups,7.5,15.0 and 30.0 mg/kg. Female mice were treated by gavage for two weeks. Follicle constituent ratio and apoptosis of ovary granulose cells were observed, and the expression levels of mch3 and bcl-2 gene were checked by RT-qPCR. Results The ratios of primordial follicle in 15.0 and 30.0 mg/kg groups and the ratio of atresic follicle in 30.0 mg/kg group were significantly higher compared with the control （P〈0.05）. The ratios of growing follicle in 15.0 and 30.0 mg/kg groups and the ratio of mature follicle in 30.0 mg/kg group were significantly lower compared with the control （P〈0.05）. With the increase in the dose of chlorpyrifos, the ratio of primordialo follicle showed increasing tendency, the ratio of mature follicle suggested decreased, the ratio of growing follicle increased at first then decreased, and the ratio of atresic follicle decreased at first then increased. The apoptosis of ovary granulose cells were significantly increased at the dose of 30.0 mg/kg （P〈0.05）, and it showed increasing tendency with the increase of the dose of chlorpyrifos. The expression level of mch3 were significantly increased at the dose of 15.0 and 30.0 mg/kg（P〈0.05）, and bcl-2 gene were significantly decreased at the dose of 15.0 and 30.0 mg/kg in a dose-dependent manner （P〈0.05）. Conclusion Chlorpyrifos may have female reproductive toxicity, through increasing the expression level of mch3 as well as decreasing the expression level of bcl-2 gene, inducing the apoptosis of ovary granu]ose cells and inhibiting the development of follicle.