镉对小鼠附睾精子参数及DNA的影响

Effect of cadmium on epididymal sperm parameters and DNA in mice

目的:对小鼠精子进行氯化镉染毒10周,观察氯化镉对精子参数及精子DNA的影响。方法:以含不同浓度的氯化镉对小鼠进行染毒,分为阴性对照组、0.25%氯化镉组、0.5%氯化镉组和1.0%氯化镉组。染毒10周后,HE染色观察睾丸形态。通过附睾上游法收集精子,手工法检测精子的浓度、活力、活率,通过HE染色观察精子形态。通过精子染色质结构分析(SCSA)和彗星试验观察附睾精子损伤情况。结果:与阴性对照组相比,染毒组小鼠的睾丸形态无明显改变;小鼠附睾精子浓度、存活率均无统计学差异(P>0.05)。与阴性对照组相比,0.5%氯化镉组、1.0%氯化镉组小鼠附睾精子活力具有统计学差异(P<0.001);各染毒组小鼠附睾精子畸形率均有统计学差异(P<0.001)。附睾精子SCSA结果显示,0.5%氯化镉组、1.0%氯化镉组的精子DFI值升高(P<0.001)。彗星试验结果显示,各染毒组的精子彗尾长度、彗尾DNA%及彗尾位移长度均比阴性对照组增加(P<0.001)。结论:低剂量氯化镉染毒10周,不影响小鼠的睾丸形态,也不影响小鼠附睾精子浓度和存活率,但影响附睾精子活力和精子形态学,氯化镉浓度越高,附睾精子DNA损伤越大。

Objective To observe the effect of cadmium chloride on sperm parameters and sperm DNA in mice exposure to cadmium chloride for 10 weeks. Methods： The mouse model of cadmium poisoning was constructed by feeding deionized water with different concentrations of cadmium chloride for 10 weeks. The mice were divided into control group, 0. 25% cadmium chloride group, 0. 5% cadmiumchloride group and 1.0% cadmium chloride group. After 10 weeks, morphological changes of testes tissue were observed by HE staining.Sperms of epididymis were collected by swim - up method. The sperm density, viability, and motility were detected by manual method, andsperm morphology was detected by HE staining. The damage of sperm was detected by sperm chromatin structure assay （SCSA） and cometassay. Results： Compared with negative control group, the morphological changes of testes showed no obvious difference in cadmium chloride groups. There was no statistically significant difference in sperm density and viability between control group and cadmium chloride groups（P 〉 0. 05 ） . There was statistically significant difference in epididymal sperm viability between negative control group and 0. 5% cadmiumchloride group, 1.0% cadmium chloride group （P 〈 0. 001 ） ; there was statistically significant difference in epididymal sperm aberration rateamong three cadmium chloride groups （P 〈0. 001 ） ; epididymal sperm SCSA showed that sperm DNA fragmentation index （DFI） value increased in 0. 5% cadmium chloride group and 1.0% cadmium chloride group, there was statistically significant difference （P 〈 0. 001 ） .Comet assay showed that sperm tail length, DNA% in tail, and tail movement in cadmium chloride groups were statistically significantlyhigher than those in negative control group （P 〈 0. 001 ） . Conclusion： Low concentration of cadmium chloride exposure for 10 weeksdoesn＇t affect the morphology of testes, sperm density and viability, but it affects sperm motility and morphology. The sperm DNA damage ismore severer with the increase of cadmium chloride concentration.