中文摘要：

研究低剂量^12C^6＋离子全身辐照对小鼠胸腺、脾脏细胞周期进程及DNA损伤的影响。以0、10、50、75、100和250mGy ^12C^6＋离子全身辐照小鼠，照射后6h处死小鼠，用流式细胞仪检测受辐照小鼠胸腺、脾脏细胞在各细胞周期的百分率，用彗星电泳技术检测受辐照小鼠胸腺脾脏细胞的拖尾率和拖尾长度。所有照射组G0／G1期胸腺细胞百分率明显低于对照组，（p〈0．05），10-100mGy照射组S期胸腺细胞百分率显著高于对照组（p〈0．01），所有照射组（G2/M）期胸腺细胞百分率明显高于对照组（p〈0．05）；所有照射组G0/G1期脾细胞百分率明显高于对照组（p〈0．01），S期脾细胞百分率显著低于对照组（p〈0．05）。彗星电泳结果显示低剂量^12C^6＋离子辐照以剂量依赖的方式引起小鼠胸腺脾脏细胞DNA迁移长度及拖尾率的增加。低剂量的碳离子辐射可促进小鼠胸腺细胞DNA合成，对小鼠脾脏细胞产生抑制作用，使其发生G1期阻滞；同时对胸腺及脾脏细胞造成具有明显剂量效应关系的DNA损伤。

英文摘要：

In order to observe the effect of low dose ^12C^6＋ irradiation on cell cycle and DNA damage in mouse thymus and spleen cells the mice were whole-body irradiated with 0, 10, 50, 75, 100 and 250mGy ^12C^6＋ ion and executed six hours after. Flow cytometry was used to test the changes on thymus and spleen cell cycle and the frequencies of cells with tail moment and the tail lengths were determined by the single cell gel electrophoresis. The results show that the percentages of G0/G1 phase cells reduce and the percentages of S phase cells increase significantly in thymus compared with control （p〈0.05）, while the percentages of G0/G1 phase cells increase and the percentages of S phase cells decrease obviously in spleen of mice （p〈0.01）. Similarly, the length of the tails and the number of cells with tail rise as the absorbed dose increased, which has the obviously dose-effect dependent relationship. Low dose ^12C^6＋ irradiation can effectively stimulate DNA synthesis in thymus and can be inhibited at G0/G1 in spleen of mice. At the same time, it can induce DNA damage along with the absorbed doses.