低氧对大鼠小肠上皮细胞辐射损伤修复的影响

Effects of hypoxia on repair of rat small intestine epithelium cell damaged by γ- irradiation

目的 探讨低氧对辐射损伤修复的影响及其可能机制。方法 以大鼠空肠上皮细胞(IEC 6细胞株)为研究对象,分正常对照组、单纯照射组和照后低氧组;6 0 Co γ射线12Gy一次性照射,低氧为5 %氧处理6h。MTT法检测细胞存活率;3H TdR掺入法检测细胞增殖;UDS和SCGE实验测定DNA损伤和修复情况;流式细胞仪检测细胞周期。结果 与单纯照射组比,照后低氧组细胞修复加快、增殖明显、存活率提高约10 % (P <0 0 1) ;G1 、G2 期阻滞延长(P <0 0 1)。结论 适当低氧能够促进细胞修复,提高存活率,其机制可能与细胞周期阻滞延长有关。

Objective To study the effects of hypoxia on repair of radiation damage and the possible mechanism. Methods Rat jejunal epithelium cell was taken as study object and divided into control group, irradiation group and irradiation-hypoxia group. The irradiation group was irradiated only once by 60 Co-γ ray at the dose of 12 Gy and the irradiation-hypoxia group was treated with hypoxia (5% oxygen) for 6 h after irradiation. MTT was used to detect the survival rate of the irradiated cells, 3H-TdR incorporation was used to detect cell proliferation, and unscheduled DNA synthesis and single cell gel electrophoresis were used to detect DNA repair and flow cytometry was used to detect cell cycle. Results As compared with the irradiation group, the cells in the irradiation-hypoxia group repaired rapidly, proliferated obviously and the survival rate was increased about 10% (P<0.01). G 1 phase and G 2 phase were prolonged. Conclusion Hypoxia can increase the cellular survival rate of IEC-6 after γ irradiation, which mechanism is possibly related to the regulation of cell cycle.