Abstract: ObjectiveTo examine the effects of arsenic on DNA damage and its X-ray repair cross complementary protein 1(XRCC1)in the spermatogenic cells of rats.MethodsForty health male Sprague-Dawley(SD)rats were randomly divided into a control group and low,moderate,and high dose group.The rats in the four groups were gavaged with different concentrations of As₂O₃ solution(0,0.375,0.75,and 1.5 mg/kg)everyday,respectively.After 16 weeks of treatment,the rats were sacrificed by cervical dislocation and the testis tissue were sampled.XRCC1 protein expression was analyzed with immunohistochemistry and DNA damage was observed with single cell gel electrophoresis test (SCGE).ResultsThe tail length of the cells averaged 1.04±0.61μm in the control group.The exposure to 0.75 and 1.5 mg/kg As₂O₃ resulted in a significant lengthening of the cell tails(3.11±1.16μm and 3.62±2.46μm,respectively, P<0.01)as well as an increased tail DNA% and tail moment of the cells(P<0.01).There was no significant difference between low dose group(16.08±9.87%)and control group(15.49±8.23%)in XRCC1 protein expression (P>0.05).XRCC1 expression in the moderate and high dose group(11.13±7.06% and 9.63±6.32%)was significantly greater than that in the control group(P<0.05).The XRCC1 protein expression of spermatogenic cells showed a dose-response relationship.The negative correlation between the DNA damage and XRCC1 expression of spermatogenic cells was significant(r=-0.778,P<0.001).ConclusionOne of the mechanisms of male reproduction toxicity of As₂O₃ might be the inhibition of XRCC1 expression which induces DNA damage.