【摘要】 目的 研究磷脂酰肌醇3-激酶的特异性抑制剂Wortmannin(WT)对小鼠胸腺细胞DNA辐射损伤修复的影响，以探索WT放射增敏作用机制。方法 以50 μmol/L WT作用小鼠胸腺细胞，以不同剂量γ射线照射，照射后不同时间制取细胞DNA，用 琼脂糖凝胶电泳方法检测DNA双链断裂(dsb)。 结果 WT单独对受照射细胞dsb产额 无明显影响，抑制照射后dsb修复。结论 WT的放射增敏剂作用与其抑制照射后dsb修复有关。

Wortmannin inhibits repairof DNA double-strand

    breaks induce d by radiation.

LI Yu,ZHAO Fang,ZHENG Xiulong etal.Department of Radiati on Medicine,The Second Military Medical University,Shanghai200433,China;

【Abstract】 Objective To study theeffect of the specific inhibi tor Wortmannin(WT)on repair of radiation damage of thymocyteDNA in mice. Method The cells were exposed to WT or DMSO(solvent)for 1 h,and th enirradiated at the indicated doses.After indicated times post irradiation,the c ells werewashed to remove the WT,their DNA was made out,then DNA damage and rep air were detectedby electrophoresis. Results After 10 Gy and 20 Gy γ-irradiation,dsb level was higher inWT group than in control group.It was m ore evident at 1-3 hrs after irradiation.Conclusion The radiosensit izing effect of WT is related to its inhibition of dsb repairafter irradiation.

     ......