辐射后单个细胞DNA结构变化的定量检测  

Quantitative Analysis of DNA StructureChanges in Individual Irradiated Cells.

作　　者：罗瑛[1] 孙志贤[1] 杨瑞彪 张振声 

机构地区：[1]北京放射医学研究所

出　　处：《生物化学与生物物理进展》1994年第5期451-453,共3页Progress In Biochemistry and Biophysics

基　　金：国家自然科学基金

摘　　要：细胞照射后可产生ＤＮＡ链断裂、ＤＮＡ－ＤＮＡ交联、ＤＮＡ－蛋白质交联等重要的ＤＮＡ结构损伤，最终可导致ＤＮＡ高级结构－ＤＮＡ超螺旋结构状态的改变，而引发ＤＮＡ复制、表达等一系列改变．参考国外报导，建立了单细胞电泳法（ｓｉｎｇｌｅｃｅｌｌｇｅｌｅｌｅｃｔｒｏｐｈｏｒｅｓｉｓａｓｓａｙ），并辅以图象分析技术，可快速检测低达０．１Ｇｙ剂量所致ＤＮＡ结构损伤，并得到了较好的剂量－效应关系，可望成为生物剂量计，用于环境低剂量辐射的监测．Irradiated cells express DNA structural dam-ages. such as DNA double-strand break.DNA-DNA crosslink and DNA-proteincrosslink etc. These damages result tochanges of DNA supercoil state, which triggera series changes of DNA replication and ex-pression. Many methods to test DNA dam-ages have been established. roughly can be de-vided into two kinds according to the DNAmaterials used. The first use the naked DNAextracted from cells and free from DNA-bind-ing materials existed in cell. The second oneuses nucleoid for research, here the detergentsand hypertonic salt buffers were used to re-move nuclear envelope and a part of nuclearproteins, nuclear DNA remains appropriatetangled loop and binds to residual nucle-arskeleton. This DNA structure is beneficialto research damage effects on DNA structure,single cell gel electrophoresis belongs to thelatter. It also named comet assay because itsceli electrophoresis shape looks like a comet.It can test not only DNA stand break but alsomeasure DNA structure changes resulted fromstand break. According to oversea reports,with slight modification, single cell gel elec-trophoresis assay has been established Em-ploying image analysis system. fast quntita-tive measurement of DNA structure changesof single cell irradiated as low as 0. 1Gy can begiven with a well correlated dose-respones re-lationship. After further study, the methodmight be developed as a kind of biodosimeterfor application of monitoring enviromental lowlevel irradiation.

关 键 词：放射损伤 细胞 DNA 结构 检测 

分 类 号：R818.740.4[医药卫生—放射医学]