中文摘要：

以不同剂量的^60Coγ射线照射人红白血病细胞系k562细胞，用流式细胞仪检测照射后24小时及不同时间点的细胞周期变化。照后24小时检测结果表明，随着照射剂量的增加，G2／M期细胞比率增加，剂量达15Gy时，出现明显的G2／M期阻滞；随着剂量的进一步增加，S期细胞比率逐渐增加，剂量达30Gy时出现明显的S期阻滞；在此剂量（5～30Gy）下，细胞凋亡未见明显变化。不同时间点的检测结果表明，随着照射剂量的增加，k562细胞从以G2／M期阻滞为主逐渐转化为以S期阻滞为主，同时细胞凋亡也明显增加。

英文摘要：

The cell cycle change of k562 leukemia cell line was investigated using flow cytometer after k562 cells were irradiated by ^60Coγ radiation of different dosage. The results from the analysis on cell cycle of k562 cells 24 h after irradiation show that the ratio of G2/M phase increased as the radiation dosage increased. The arrest of G2/M phase took place at 15 Gy dose of ^60Coγ radiation. After that, the radiation dosage increased companied with increasing the rate of S phase. The arrest of S phase took place at 15 Gy dose of ^60Coγ radiation. The apoptosis did not change in the 5 to 30 Gy range. The results at different time show that the arrest of G2/M phase was changed to the arrest of S phase along with the increasing dosage, and the apoptosis increased apparently.