放射性核素内照射诱发大鼠外周血淋巴细胞HPRT基因位点突变与染色体畸变的研究

HPRT gene locus mutation and chromosomal aberration in rat peripheral blood lymphocytes induced by internal exposure to radionuclides

目的 阐明放射性核素内照射诱发外周血淋巴细胞HPRT基因位点突变的剂量效应关系 ,并与染色体畸变剂量效应关系进行比较。方法 给动物尾静脉注射放射性核素 ,注射量为0 5ml/ 10 0 g体重。剂量效应关系组动物注射活度为 3 64× 10 5Bq/ml,于注射后 1、3、6和 9d心脏穿刺取血。剂量率效应关系组动物注射活度分别为 3 64× 10 5、1 82× 10 5、0 91× 10 5和 0 4 45×10 5Bq/ml,于注射后 3、6 7、17和 4 2d心脏穿刺取血。应用多核细胞法及胞质分裂阻断法 (CBMN)和常规染色体畸变分析法检测HPRT基因位点突变率和染色体畸变率。用计算机拟合剂量效应关系和剂量率效应关系函数。结果 淋巴细胞HPRT基因位点突变率不仅随内照射剂量和剂量率增加而增加 ,呈现出良好的正相关 ,而且与染色体畸变亦呈现出较好的相关性。

Objective\ HPRT gene locus mutation in rat peripheral blood lymphocytes induced by internal exposure to radionuclides was performed,and compared with chromosomal aberration. Methods Rats were injected intravenously with radionuclides of specific activity of 3 64×10 5 Bq/ml for the study of dose\|effect relationship and 3 64×10 5,1 82×10 5,0 91×10 5,0 455×10 5 Bq/ml respectively for the study of dose rate\|effect relationship.The blood was sampled at different times after injection.HPRT gene mutation frequency(GMF) and chromosomal aberration frequency (CAF) were examined by methods of multinucleus cell assay,cytokinesis\|block micronucleus (CBMN) and chromosome aberration assay.Dose\|response functions were fitted with a computer. Results GMF and CAF did not increase with increase of dose and dose\|rates but were clearly interrelated between GMF and CAF. Conclusion The HPRT gene mutation may be used as a biological dosimeter.\;