亚慢性镉中毒所致小鼠睾丸、精子损伤及锌保护作用研究

Effect of subchronic cadmium exposure on testicles and sperms of male mice and the protective effect of zinc sulfate

目的 了解亚慢性镉中毒对睾丸及精子的损伤及锌保护作用。方法 以ICR小鼠为研究对象 ,以不同剂量的氯化镉 ( 0 4,0 8,3 2mg/kg)每周连续 4次背部皮下注射染毒 ,连续 7周 ;皮下注射 1 6mg/kg氯化镉溶液的同时给予 3 5 0 μg/ml硫酸锌水溶液喂饲 7周为锌保护组。建立亚慢性镉中毒模型 ,并观察锌对镉所致睾丸组织病理改变以及对附睾精子畸变的影响。实验同时设立阴性对照组 (蒸馏水 ,ip)和精子畸变阳性对照组 (处死前 6d给予环磷酰胺 5 0mg/kg ,ip ,连续 2d)。结果 随着染毒剂量的增加 ,低、中、高各剂量组睾丸组织异常病理变化及精子畸形率呈逐渐增高趋势 ,表现出明显的剂量 反应关系。锌保护组与高、中染毒组比 ,精子畸变率明显降低 ,而与低剂量组和阴性对照组比较精子畸形率差异无显著性 ;同时镜下病理表现仅见生精细胞上皮层次略有减少 ,成熟精子数无减少现象 ,损伤程度明显低于相应染毒组。结论 镉对小鼠的睾丸和附睾有明显的毒性作用 。

Objective To explore the subchronic toxicity of cadmium on testicles and sperms and the protective effect of zinc sulfate.Method 62 ICR male mice were randomly divided into 7 groups.Four treated groups were injected subcutaneously with different doses(0.4mg/kg,0.8mg/kg,3.2mg/kg)of cadmium chloride (CdCl 2)for 7 weeks(once a day,four days per week).Zn-treating mice were injected with CdCl 2(1.6mg/kg)and given zinc sulfate(350 μg/ml)in drinking water.Additionally,there were two control groups:distilled water negative control group and cyclophosphamide positive control group.At the end of the experiment, the pathologic changes of testicle tissues were rate of the sperm malformation were detected.Result There was a good dose-response relationship between the dose of cadmium chloride and sperm malformation rate in the 0.4,0.8,1.6mg/kg treated groups,no sperm could be seen in the mice of 3.2mg/kg treated group.Pathologic changes of testicles were also aggravated with the dose of cadmium chloride.The testicles in the mice of 3.2mg/kg treated group showed calcified and atrophied.Zinc sulfate can reduce the sperm malformation rate and improve the pathologic changes of testicles.Conclusion It is suggested that cadmium has subchronic toxicity on testicles and can induce malformation of sperms,and zinc has protective effect on the toxicity of cadmium to a certain extent.