Effects of As_2O_3 on Apoptosis and Telomerase Activity of Rat Spermatogenic Cells

Objective To investigate the effect of arsenic(As2O3) on spermatogenic cell apoptosis and the expression of telomerase activity in adult rats.Methods 40 healthy male Sprague-Dawle rats were randomly divided into four groups and they were treated with As2O3 at doses of 0(control group),0.375,0.75 and 1.5 mg/kg body weight respectively through gavage for 16 consecutive weeks.The numbers of testicular sperm head were counted and the coefficient of testicular viscera,daily sperm production(DSP) were calculated in every group.The apoptosis of germ cell was assessed by in situ terminal deoxynucleotityl transferase mediated dTUP nick end labeling(TUNEL) technique.The activity of telomerase in the spermatogenic cells was determined by immunohistochemistry.Results In the testes of As2O3-treated rats,the coefficient of testicular viscera,the number of testicular sperm head and DSP in moderate and high dose groups decreased significantly than that of control(P0.01).The apoptosis index of germ cell(AI) significantly increased compared with the control group(P0.01).The activity of telomerase in moderate dose group and high dose group decreased significantly compared with the control group(P0.01).The dependability analysis between DSP and AI showed a negative correlation(r =-0.563,P0.01).The negative correlation was significant between AI and telomerase activity of spermatogenic cells(r=-0.896,P0.01).Conclusion Telomerase activity inhibition is related to the sperm cells decrease caused by arsenic exposure.