Suzuki M, Yang Z, Nakano K, Yatagai F, Suzuki K, Kodama S, Watanabe M
National Institute of Radiological Sciences, Chiba, Japan.
J Radiat Res. 1998 Sep;39(3):203-13. doi: 10.1269/jrr.39.203.
We studied the effect of repeated irradiation with a low dose rate (about 0.0012 cGy per min) of 60Co gamma-rays on the in vitro life-span of human embryo (HE) cells. HE cells were cultured in an incubator that was set in a 60Co gamma-ray-irradiation room, and the irradiation was repeated throughout the life-span of the HE cells (for about 150 to 160 days) on every day base. During this period, the cells accumulated 106 to 123 cGy. The life-span of the irradiated cells prolonged 1.14 to 1.35 times when compared to that of non-irradiated cells. The incidence of cells with chromosome bridge and micronuclei significantly increased in the irradiated cells. Although the number of chromosomes gradually changed with repetition of culture in both non-irradiated and irradiated cells, the frequencies of aneuploid cells in irradiated cells were about two times higher than that in non-irradiated cells. These results indicate that repeated irradiation with a low dose of gamma-rays produces chromosome instability, and it may be a cause of numerical chromosome abnormalities and life-span extension of irradiated cells.
我们研究了以低剂量率（约每分钟0.0012厘戈瑞）重复照射60Coγ射线对人胚（HE）细胞体外寿命的影响。将HE细胞培养于置于60Coγ射线照射室的培养箱中，在HE细胞的整个寿命期（约150至160天）内每天重复进行照射。在此期间，细胞累积了106至123厘戈瑞的辐射剂量。与未照射细胞相比，照射细胞的寿命延长了1.14至1.35倍。照射细胞中具有染色体桥和微核的细胞发生率显著增加。尽管在未照射和照射细胞中，随着培养的重复进行染色体数量逐渐发生变化，但照射细胞中非整倍体细胞的频率比未照射细胞高约两倍。这些结果表明，低剂量γ射线的重复照射会导致染色体不稳定，这可能是照射细胞中染色体数目异常和寿命延长的一个原因。
