单能质子辐射致质粒DNA链断裂的剂量效应  

The Dose Effect on DNA Radiation Damage Induced by Protons

作　　者：孔福全[1] 王潇[1] 隋丽[1] 倪嵋楠[1] 杨明建[1] 赵葵[1] 

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《激光生物学报》2008年第3期291-294,共4页Acta Laser Biology Sinica

基　　金：国家自然科学基金项目(10435020)

摘　　要：利用16.4 MeV的质子在不同的剂量下辐照质粒DNApUC19溶液。凝胶电泳技术的分析结果表明随着辐照剂量的增加,DNA损伤变得越来越严重,使线性DNA成分明显增加。当添加了自由基清除剂甘露醇后,DNA的损伤明显减轻,线性DNA片段不再出现,但开环形态DNA的变化依然明显。与较早的重离子7Li和γ射线致DNA损伤的研究结果相比较,表明质子辐射中还是存在着一定的直接作用,在此次实验的能量和LET值范围内,质子的直接电离作用是高于γ射线而低于7Li离子的。To measure the DNA lesions and the form of transformation in plasmid DNA irradiated with protons, the plasmid DNA samples were irradiated with 16.4 MeV proton （linear energy transfer = 3.12 keV/μm） in aqueous solution containing 0 mmol/L or 600 mmol/L mannitol. DNA were measured by gel electrophoresis and Alpha Innotech digital imaging system. For proton without mannitol, DNA lesions were very evident at the dose ofSO Gy. The fractions of SC form and OC form decreased till they disappeared with increasing doses. The Short fragments of DNA came forth at the dose of 300 Gy. In the presence of 600 mmol/L mannitol, DNA lesions were restrained. However the fraction of OC form increased obviously with increasing doses, which showed that there are some direct damages with the proton irradiation. These provide important experimental data for the dangerous assessment of space radiation and proton therapy.

关 键 词：质子 剂量 辐射 质粒DNA 

分 类 号：Q691[生物学—生物物理学]