γ射线照射后HeLa细胞端粒酶活性变化及机制探讨

[目的]观察射线照射后细胞端粒酶活性变化，并探讨其机制。[方法]HeLa细胞体外培养。照射2、4、8和20Gv后，分别于0、2、4、8、12、24、72和168h收集细胞．测定端粒酶活性、凋亡指数和’H掺人量。另取定量细胞照射0，1．2，3，4，6，8和10Gv．培养7d后。计算细胞存活率。[结果]2Gy和4Gy γ射线照射后．HeLa细胞端粒酶活性在短时间内上升，然后下降；8Gy和20Gy γ射线照射后酶活性迅速下降，并保持低水平。[结论]辐射后细胞端粒酶活性呈现规律性变化，这种变化是细胞死亡、亚致死损伤修复和存活细胞调节的综合结果。

The Change of Telomerase Activity in Hela Cells After Gamma-ir radiation and Its Mechanism

[Purpose] To investigate the change of telomerase activity in Hela cells after radiation and its mechanism. [Methods] HeLa cells were incubated in vitro. The cells growing at exponent growth phase were exposed to gamma rays at doses of 2,4,8 and 20Gy,and cells were collected after 0,2,4,8,12,24,72 and 168h respectively.Then telomerase activity, apoptosis index and the amount of 3H incorporation were detected. Another cells were irradiated with escalated doses, then grown continually and calculated the cell survival rate in 7 days. [Results] After irradiation by 2Gy , 4Gy, the telomerase activity in HeLa cells was going up in short time, and then declined, but irradiation by 8Gy and 20Gy made the activity decrease rapidly and then maintained at low level of activity.[Conclusion] The changes of telomerase activity in Hela cells after exposing to ionizing was differed in different doses, but have a correlated tendency. The changes are comprehensive results with cells death, repairing of damage and regulation of residual cells.