Objective   To establish the model of subchronic cadmium exposure in mice, and study the effect of DNA damage of testicle cells at the same time, the protective effect of zinc sulfate(ZnSO₄)on subchronic exposure were also stud2 ied.

  Methods   Four groups of ICR mice were injected everyday with cadmium chloride by the different dose(0.4, 0.8, 1.6 mg/kg, )for 7 weeks.The group of 1.6 mg/kg also fed with ZnSO₄.When the exposure was finished, the concentration of cadmium in blood and liver were determined by atomic absorption spectrophotometer, and the morphological changes of testes were also observed.The single cell gel electrophoresis(SCGE, Comet assay)technique was used to detect the DNA damage of testicle cells.

  Results   Cadmium concentration in blood and liver in the exposure groups increased along with the exposure dose of cadmium contents increased.The results of coefficient viscera of testes, the pathological changes, and the DNA damage levels of testicle cells showed that cadmium could damage the testes to a different degree in a good dose-effect relationship manner.If ZnSO₄ was used in the group of cadmium chloride(1.6 mg/kg)exposure, the pathological damages of testes were decreased even near to the levels of control group, but at the same time, the DNA damage of testicle cells were not improved by Zinc.

  Conclusion   The model of subchronic cadmium-exposed mice was set up successfully.Cadmium exposure may induce the DNA damage of testes cells, zinc sulfate could improve the subchronic pathological damage in testes induced by cadmium in a certain degree, but the protective effect of zinc was not showed in DNA damage level.