^60Coγ射线超大剂量照射离体人外周血染色体畸变的剂量-效应研究  

Dose-effect of chromosome aberration in lymphocytes of human peripheral blood irradiated with high dose of ^60Coγ rays in vitro

作　　者：姚波[1] 李玉芳[1] 刘广贤[1] 黄珊[1] 蒋本荣[1] 艾辉胜[1] 

机构地区：[1]军事医学科学院附属医院,全军放射病中心,北京100071

出　　处：《中华放射医学与防护杂志》2009年第5期468-471,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的探讨超大剂量7射线离体照射后人外周血淋巴细胞染色体畸变的量效关系，建立双＋环（dic＋r）大剂量．效应曲线。方法外周静脉血样采自3名健康男性，经^60Coγ线（0—50Gy，剂量率2．35Gy／min）照射。采用即刻加秋水仙素的微量全血法，分别培养52、72及96h。计数有丝分裂指数（MI）、双着丝粒体（die）和环（r）畸变数，拟合die＋r剂量．效应曲线，对2例受大剂量照射的事故患者进行剂量估算。结果MI随照射剂量的增加而逐渐减少。每细胞dic＋r频率随照射剂量增加而增加直到23Gy（5Gy之后增加幅度较前变小），〉23Gy后趋于饱和。对所获数据进行回归分析，拟合djc＋r大剂量．效应曲线（5—23Gy）：每细胞dic＋r频率y=-1．608（±0．300）＋0．830（±0．051）D-0．013（±0．002）D^2（R^2=0．998）。用拟合曲线对2例受照患者剂量的估算结果与用物理方法和电子自旋共振（ESR）法估算的剂量及临床表现基本一致。结论本研究建立的die＋r大剂量-效应曲线，可估计的上限剂量达23Gy，有可能提高常规染色体畸变分析用作生物剂量计的实用价值。Objective To explore the dose-effect of chromosome aberration, and establish a dose-effect curve of dicentric and ring （dic ＋ r） in human peripheral blood lymphocytes irradiated with high dose of γ-rays. Methods Human peripheral blood was obtained from three healthy individuals, and exposed to ^60Coγ-rays with doses between 0 and 50 Gy. Colchieine was added immediately and the cells were incubated at 37℃ for 52,72 and 96 h, respectively. Metaphase index （MI） and dic ＋ r were counted, and a dose-effect curve was fitted. Dose estimation were performed according to the curve for the two patients who had accidentally received high doses of irradiation. Results MI was reduced with the dose increasing. Frequencies of dic ＋ r were increased until 23 Gy, and then saturation was observed. A dose-effect curve was fitted during 5-23 Gy, and the doseeffect was as follows： y= - 1.608（±0.300） ＋0.830（±0.051）D-0.013（±0.002）D^2（R^2 =0.998）, where y is the yield of die ＋ r, and D is the dose. The dose estimated for the two patients were in accordance with those by physical method, ESR method and clinical symptoms. Conclusions The highest dose that could be estimated is 23 Gy with the established die ＋ r dose-effect curve by using the colchicine block method and prolonged culture time, which suggests the potential of chromosome aberration analysis as biological dosemeter.

关 键 词：超大剂量照射 染色体畸变 剂量-效应曲线 

分 类 号：R144[医药卫生—公共卫生与预防医学]