甲氧滴滴涕对大鼠雌性性腺的毒性作用

Toxic effect of methoxychlor on the female rat gonad

目的:通过亚慢性甲氧滴滴涕(MXC)染毒,观察MXC的雌性性腺毒性.方法:使用雌性SD大鼠作为实验动物,3mo龄,随机分为4组,每组10只,染毒剂量分别为0(对照)、16(低剂量)、32(中剂量)、64(高剂量)mg/(kg.d),对照组给予等剂量芝麻油,所有实验大鼠均通过腹腔注射染毒,连续20d.每天用阴道脱落细胞涂片法连续观察并记录动情周期.染毒结束后于动情期将大鼠处死,观察指标包括体质量,卵巢、子宫的脏器系数;运用光镜计数各级卵泡及黄体数目.结果:①染毒前后各组体质量增加未见显著差异;②中高剂量染毒组动情期延长,周期数减少;③中高剂量组卵巢体质量及卵巢指数显著降低;④中高剂量组闭锁卵泡显著增加,且次级卵泡闭锁率显著升高;结论:①甲氧滴滴涕可以使动情周期延长,卵泡闭锁增加,对雌性性腺产生毒性;②低剂量组未对雌性性腺产生明显的影响.

AIM：To study the relation between female gonad toxicity of methoxychlor（MXC） on rats,subchronic methoxychlor effect on the female gonad was carried out.METHODS：Forty female SD rats were randomly divided into 4 groups,4 different dose levels [0,16,32 and 64 mg/（kg·d） MXC] were injected intraperitoneally accordingly for 20 d.Vaginal smears of rats were performed to determine estrous cycle.The rats were sacrificed on the day of estrus stage.Body weights,estrus stage,organ weights and organ coefficients of ovary were observed.Uterine tissue and ovary were prosessed for histologic examination.RESULTS：①Increasing of body weight was not different between 4 groups after treatment.②Estruation was prolonged in MXC 32 and 64 mg groups,periodicity decresed accordingly.③Organ weights and organ coefficients of ovaries in rats treated with MXC 32 and 64 mg groups were significantly different from the control group.④Numbers of atresic follicle were significantly increased in both the MXC 32 and 64 mg groups,the atresic rate of secondary follicle was significantly increasd.CONCLUSION：①MXC could result in prolonged estruation circle and increased number of atresic follicle.②No significant influence on female gonads toxicities was found in low-dose group.