质子剂量和DNA浓度对DNA损伤的影响  

Effect of dose and DNA concentration on DNA damage induced by protons

作　　者：隋丽[1,2] 王潇[1] 周平坤[2] 倪嵋楠[1] 孔福全[1] 杨磊[1] 刘建成[1] 赵葵[1] 

机构地区：[1]中国原子能科学研究院,北京102413 [2]军事医学科学院放射与辐射医学研究所,北京100850

出　　处：《核技术》2011年第6期447-451,共5页Nuclear Techniques

基　　金：国家自然科学青年基金(10805078);国家杰出青年科学基金(30825011)资助

摘　　要：利用HI-13串列加速器产生的16 MeV质子,使用凝胶电泳技术对添加和未添加甘露醇的pUC19质粒DNA溶液中DNA分子形态变化进行了观测,研究了同一剂量下不同DNA浓度及同一DNA浓度下不同剂量对DNA链断裂产额的影响。结果表明,未添加甘露醇溶液中DNA浓度效应较明显。两种体系下DNA均表现出明显的剂量响应,即分子形态由完整的超螺旋形态逐渐向发生单链断裂的开环形态或双链断裂的线性形态变化,且未添加甘露醇的体系链断裂产额相对更高,表明甘露醇可清除自由基,有效降低质子致DNA单链和双链断裂的发生。此外,还研究了10 ng/μL和100 ng/μL DNA浓度下,不同剂量对DNA损伤的影响。结果显示,DNA溶液浓度越低,达到同样损伤所需的辐照剂量越小。The pUC19 plasmid DNA solutions in different DNA concentrations,with or without mannitol,were irradiated by 16 MeV protons to different doses.Changes in the DNA form were observed by means of gel electrophoresis in order to study effects of dose and DNA concentration on yields of DNA strand breaks.The results indicate that the dose and DNA concentration response exist in two solution systems,the forms of DNA changed from intact supercoiled to open circular,in a linear relationship with the dose.The yields of DNA strand breaks in DNA solution without mannitol are much more than that those with mannitol,illuminating that mannitol can scavenge the free radicals and reduce the yields of DNA single and double strand breaks induced by protons efficiently.In addition,the dose effects of DNA damage were investigated at a concentration of 10 or 100 ng/？L.The results show that dilute DNA solution need lower dose than the dense solution in observing similar degree of damage.

关 键 词：质子 质粒DNA 双链断裂 DNA浓度 

分 类 号：Q523[生物学—生物化学] Q691