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目的探讨断乳至性成熟期经口持续摄入纳米二氧化硅对小鼠卵巢发育的影响。方法将40只21日龄清洁级ICR雌性小鼠随机分为4组,即对照组和0.25、0.50、1.00 g/kg纳米二氧化硅染毒组,每组10只。采用经口灌胃方式进行染毒,每日1次,持续染毒5周。实验结束后记录小鼠体重增长情况、观察阴门开放时间和动情周期,病理切片计数各级卵泡数量及计算各级卵泡的构成比,并测定卵巢中丙二醛(MDA)含量和超氧化歧化酶(SOD)、谷胱苷肽过氧化物酶(GSH-Px)活力。结果与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢重量和脏器系数下降、阴门开放时间推迟、卵巢黄体构成比下降、闭锁卵泡构成比升高,差异有统计学意义(P<0.05);而各剂量纳米二氧化硅染毒组小鼠体重增长和动情周期均无明显改变。与对照组比较,1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中MDA含量明显上升,SOD活力均明显下降,而0.50、1.00 g/kg纳米二氧化硅染毒组小鼠卵巢组织中GSH-Px活力均升高,差异具有统计学意义(P<0.05)。结论经口摄入纳米二氧化硅可影响小鼠卵巢发育,其机制可能与氧化损伤有关。
Objective To investigate the effect of continuous oral administration of nano-silica from weaned to sexual maturity on ovarian development in mice. Methods Twenty-four female mice of 21-day-old clean-grade ICR were randomly divided into 4 groups, namely control group and 0.25,0.50,1.00 g / kg nano-silica exposure group, 10 rats in each group. Oral gavage by way of exposure, once daily, continued exposure for 5 weeks. At the end of the experiment, the growth of mice was recorded, the time of vulva opening and estrous cycle were observed, the number of follicles at all levels was calculated and the constituent ratio of follicles at various levels was counted. The contents of malondialdehyde (MDA) and superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) activity. Results Compared with the control group, the weight and organ coefficient of ovary in mice treated with 1.00 g / kg nano-silica decreased, the opening of the vulva was delayed, the ratio of corpus luteum composition decreased, and the constituent ratio of atresia follicles increased, the difference was statistically significant (P <0.05). However, there was no significant change in weight gain and estrous cycle in mice exposed to nano-silica at all dosages. Compared with the control group, the content of MDA in the ovarian tissue of 1.00 g / kg nano-silica group increased obviously and the activity of SOD decreased obviously. However, the ovarian tissue of mice in the group of 0.50 and 1.00 g / kg nano- In the GSH-Px activity were increased, the difference was statistically significant (P <0.05). Conclusion Oral intake of nanosilica can affect ovarian development in mice, and its mechanism may be related to oxidative damage.