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[目的]比较~(60)Coγ射线、X射线和~(137)Csγ射线对人外周血淋巴细胞微核率的影响,并探讨其在低剂量受照者剂量估算中的应用意义。[方法]在0～1.00 Gy的剂量范围内,用~(60)Coγ射线、X射线和~(137)Csγ射线(剂量率分别为0.440、0.073、0.810Gy/min)照射离体人血,采用胞质分裂阻断微核法(cytokinesis-block micronucleus method,CB微核法)培养和制片,计数分析双核CB细胞中微核率和微核细胞率,拟合剂量-效应曲线,并计算不同射线的相对生物效能(relativebiological effectiveness,RBE)。[结果]正常人群中微核自发率很低。采用0.05～1.00 Gy的~(60)Coγ射线、X射线和~(137)Csγ射线照射离体人血后,诱发的淋巴细胞微核率和微核细胞率均随照射剂量增加,二者呈正相关(P<0.01)。采用二次多项式拟合的微核剂量-效应曲线回归方程分别为(?)_1=4.8473+59.3422D+37.3649D~2(~(60)Coγ射线)、(?)_2=1.6209+55.1308D+12.6504D~2(X射线)和Y_3=5.0859+7.5269D+37.2330D~2(~(137)Csγ射线),曲线的拟合指数(R~2)分别为0.9827、0.9948和0.9986,回归系数有统计学意义(P<0.001)。不同类型、不同能量的辐射诱发CB微核的RBE不是单一值,尤其在低剂量辐射照射时RBE值较大。[结论]辐射诱发的淋巴细胞微核与辐射剂量有良好的回归关系,建立的剂量-效应曲线可为低剂量照射的医疗救治和预后评估提供生物剂量估算依据,但需充分考虑辐射类型和辐射能量。
[Objective] To compare the effect of ~ (60) Coγ-ray, X-ray and ~ (137) Csγ-ray on the micronucleus rate of human peripheral blood lymphocytes and to explore its significance in the dose estimation of low-dose irradiation. [Methods] In vitro human blood was irradiated with ~ (60) Coγ-ray, X-ray and ~ (137) Csγ-ray at dose rates of 0.440,0.073,0.810Gy / min in the dose range of 0 ~ The cytokinesis-block micronucleus (CB) micronuclei method was used to culture and prepare the cells. The micronucleus rate and micronucleus rate in binuclear CB cells were counted and the dose-response curves were fitted and calculated The relative biological effectiveness (RBE) of different rays. [Result] The spontaneous rate of micronucleus in normal population is very low. After irradiated with ~ (60) Coγ-ray, X-ray and ~ (137) Csγ-ray from 0.05 to 1.00 Gy, the micronuclei and micronuclei of lymphocytes were all increased with the irradiation dose Related (P <0.01). The regression equation of dose-effect curve of micronucleus fitted by quadratic polynomial was (?) _1 = 4.8473 + 59.3422D + 37.3649D ~ 2 (~ (60) Coγ ray) The curve fitting index (R ~ 2) was 0.9827, 0.9948 and 0.9986 respectively with the regression coefficients of 12.6504D ~ 2 and Y_3 = 5.0859 + 7.5269D + 37.2330D ~ Statistical significance (P <0.001). The RBE of CB micronucleus induced by radiation of different types and energies is not single value, especially when the dose of RBE is relatively low. [Conclusion] There is a good regression relationship between radiation-induced micronuclei of lymphocytes and radiation dose. The established dose-response curve can provide biological dose estimation basis for medical treatment and prognosis evaluation of low-dose irradiation, but radiation type and radiation energy.