中子辐射诱发人外周血染色体畸变、微核HPRT基因突变的比较研究

目的研究中子辐射诱发离体人外周血淋巴细胞染色体畸变率、微核率和HPRT基因突变率作为中子辐射的生物剂量计的可能性。方法采用14MeV中子等剂量率照射离体人外周血,吸收剂量范围0~1Gy,秋水仙素阻断法检测染色体畸变率,CB细胞法和常规培养法检测微核率,多核细胞法检测HPRT基因突变率,建立相应的剂量效应曲线,比较各指标间的相关性。结果在该剂量范围内,各指标与剂量关系符合现行平方模型,染色体畸变、微核呈过离散分布,三者有线性相关性。染色体畸变率灵敏度最高,其次是CB细胞法微核率,再次是常规培养法微核率,HPRT基因突变率最低。结论中子辐射事故可采用准确灵敏的染色体畸变率和CB细胞法微核率作为生物剂量计进行辐射种类判定和生物剂量估算。

Comparative Study on Human Peripheral Blood Chromosome Aberration,Micronucleus and HPRT Gene Mutation Induced by Neutron Irradiation

Objective To study the possibility of using human peripheral blood lymphocytes ehro- mosomal aberration, micronucleus and HPRT gene mutation rates induced by neutron irradiation in vit- ro as biological dosimeter. Methods Forteen MV neutron radiation isodose rate was used to treat hu- man peripheral blood lymphocytes in vitro with a dose range from 0 to 1Gy, Colchicine block,cylosine B （CB） stimulated lymphocyte culture, conventional lymphocyte culture, mullinuclear cell method were used to detect the chromosomal aberration rate,the micronucleus frequency and the HPRT gene mutation rate,reapectively,the corresponding dose-response curves were established.The relativities between any two of these indicators were compared. Results In the range of dose used, the relationship of dose and indicator accorded with the current square model. The chromosome aberration rates and micronucleus frequencies presented over discrete distribution.There existed linear correlations among three indicators of them,the chromosome aberration rate was the most sensitive one, followed by CB cell micronucleus frequency, conventional culture micronucleus frequency and HPRT gene mutation rate indiscent order. Conclusion In Neutron accidents,the sensitive and accurate chromosome aberration rate and CB cul- ture micronucleus frequency can be used as biological dosimeter to determine the type of radiation and to estimate its biological dose.