离子注入不同辐射敏感性微生物自由基与存活关系的研究

The relation of ESR spectrum and survival by N + ion implantation in D.radiodurans and Ecoli

以不同辐射敏感性微生物耐辐射异常微球菌（Ｄｅｉｎｏｃｏｃｃｕｓｒａｄｉｏｄｕｒａｎｓ）和大肠杆菌（Ｅ．ｃｏｌｉ）为试材，用电子自旋共振（ＥＳＲ）波谱法研究了离子注入后在两种微生物细胞内产生的自由基及其与存活的关系。结果表明，Ｎ＋离子注入２４ｈｒ后，其细胞内均产生了波形相似、信号强度较大的ＥＳＲ波谱单一峰，且强度随注入剂量的增大而增大，当剂量达到６０×１０１４ｉｏｎｓ／ｃｍ２时，自由基的产额趋于饱和；用·ＯＨ和·Ｈ自由基清除剂甲酸钠作后处理，降低了其ＥＳＲ波谱信号的强度，提高了存活率；研究还证实了两种微生物的辐射敏感性与离子注入后其本身对自由基的清除能力有直接关系。

The influence of the longevity free radicals formed by N + ion implantation in different radiosensitivity microorganisms on survival and the ESR(Electron Spin Resonance) spectrum characteristics of thes free radicals in D.radiodurans and E.coli were investigated with the method of ESR and biological statistics. The results were as follows:first, ESR spectrum signal of free radicals in the cell of D.radiodurans and E.coli was stronger than that of control by N + ions implantation in 24 hours, and that increased with increasing implantation dose, the content of free radicals reached saturation when implantation dose exceeded 60×10 14 ions/cm 2; second, the intensity of ESR spectrum signal was all weakened , yet survival rate of them was raised by 50mM sodium formate(scavenger of ·OH and ·H free radicals) solution pretreatment; finally, the relation of free radical and radiation sensitivity was discussed.