铅对小鼠睾丸细胞DNA损伤作用研究

目的:通过建立亚慢性铅中毒动物模型探讨醋酸铅对雄性小鼠睾丸细胞DNA的损伤,为进一步了解其毒性作用机制提供科学依据。方法:将45只雄性小鼠分为0.2%、0.4%染铅组及空白对照组,每组各5只。实验组醋酸铅溶于去离子水中供小鼠自由摄取,空白对照组饮用自来水。分别于第2、4、6周分别处死动物,用单细胞凝胶电泳实验(彗星实验)检测小鼠睾丸细胞DNA损伤情况。结果:醋酸铅染毒后小鼠睾丸细胞DNA单链断裂,出现彗星状拖尾。无论是拖尾细胞的百分率,DNA迁移的长度,还是olive尾矩与空白对照组相比其差异具有极显著性(P<0.01),并且随着醋酸铅染毒浓度和时间的增加DNA的损伤越重,呈现出时间-效应关系。但0.2%与0.4%各周染毒组的拖尾细胞百分率、彗星尾长、olive尾矩的差异并无显著性(P>0.05)。结论:醋酸铅可诱导睾丸生殖细胞DNA损伤,并且其损伤作用呈现出时间依赖性。

Effect of Lead on DNA Damage of Testicular Cells in Mice

Object: To establish the model of subchronic lead exposure in mice , and explore the effect of DNA damage of testicular cells in order to provide the scientific basis for further understanding of the mechanism of testicular toxicity. Method: 45 mice were divided randomly into 0.2%, 0.4% lead exposed group and blank control group( 5 mice in each group). Experimental groups were exposed by drinking freely solution that lead acetate suspended deionized water, tap water in control group. 5 mice in each group were put to death at two, four and six weeks respectively, the effects of lead acetate on DNA damage in mice testicular cells were detected with single cell gel-electrophoresis test ( Comet assay ). Result: Lead acetate induces the breakage of DNA single strand in testis and resulted in comet cells with tail. The number of comet cells, the length of DNA migration and olive tail moment in lead exposed groups were significantly higher than that of control(P<0.01). Furthermore, they were increased with the increasing of concentration and time of lead exposure, showing the obvious time-effect relationship. But there were no significant difference between 0.2% and 0.4% lead exposed group(P>0.05). Conclusion: Lead acetate can induce DNA damage in mice testes, and the effect is time-independent.