关键词: 
辐射 /
低剂量辐射超敏感性 /
DNA损伤修复 /
细胞周期阻滞

摘要: 细胞低剂量辐射反应是目前国际上研究的热点。 介绍了哺乳动物细胞的低剂量反应——辐射超敏感性(HRS)和增强的辐射抗性(IRR)， 即细胞在大约0.1 Gy时会出现单位剂量细胞杀伤增强现象， 随着剂量的升高， 细胞的IRR增强， 到1 Gy以上细胞存活符合线性平方模型。 评述了近年来国际上低剂量HRS领域的研究进展， 着重讨论了HRS/IRR可能的分子机理及辐射传能线密度与HRS/IRR的关系， 并对HRS/IRR在肿瘤临床放射治疗中的应用做了初步的探讨， 最后提出了该领域进一步研究的一些问题。At present, cell response to low dose radiation is attracting growing interests all over the world. Hyperradiosensitivity (HRS) and increased radioresistance (IRR) were introduced in this paper. This phenomenon means that an excess cell killing per unit dose appears at about 0.1 Gy (HRS) and then the cell radiation sensitivity increases with increasing dose (IRR). When the dose outstrips 1 Gy, the cell surviving fraction coincides with the value predicted by the commonly accepted linearquadratic (LQ) model. We further reviewed the progress to date in the study of low dose HRS, especially the possible molecular mechanisms underlying HRS/IRR and the relationship between HRS/IRR and linear energy transfer (LET). An initial insight into the clinical application of HRS/IRR in tumor radiotherapy was presented as well.Moreover, several topics concerning the HRS/IRR investigation, which deserved to be reinforced, were put forward.