不同条件微波辐射对PC12细胞周期、死亡方式和超微结构的影响

Effect of microwave radiation under different conditions on the cell cycle,cell death mode and ultrastructure of PC12 Cells

目的探讨不同条件微波辐射对PC12细胞的损伤效应,为深入研究微波辐射的损伤机制提供剂量学依据。方法采用平均功率密度(重复频率×脉宽)分别为10 m W/cm2(100 pps$500 ns)、30 m W/cm2(300 pps$500 ns)和30 m W/cm2(1000 pps$150 ns)的微波辐射NGF诱导后的PC12细胞5 min,于辐射后6 h,采用流式细胞术检测细胞周期、凋亡和坏死率,采用激光扫描共聚焦显微镜观察细胞凋亡和坏死率,采用透射电镜观察PC12细胞超微结构的改变。结果10 m W/cm2(100 pps$500 ns)辐射后6 h,G0-G1期PC12细胞数减少(p<0.05),G2-M期细胞数增加(p<0.01);30 m W/cm2(1000 pps$150 ns)辐射后6 h,G0-G1期细胞数增加(p<0.05),G2-M期减少(p<0.01);30 m W/cm2(300 pps$500 ns)辐射后6 h,G0-G1期细胞数增加(p<0.05),S期细胞数减少(p<0.01),细胞凋亡率增加(p<0.01),PC12细胞核膜间隙增宽,染色质浓缩边集,核仁呈蜂窝状;线粒体肿胀、空化。结论 30 m W/cm2(300 pps$500 ns)微波辐射可引起PC12细胞生长抑制,凋亡率增加,结构损伤;30 m W/cm2(300 pps$500 ns)可作为深入研究微波辐射的损伤机制的辐射剂量。

Objective The purpose of this study was to investigate the effects of microwave radiation under different conditions on rat pheochromocytoma PC12 cells and to provide the dosage information for studies of mechanisms of microwave radiation. Methods Nerve growth factor （NGF） -induced PC12 cells were ex- posed to microwave radiation for 5 minutes. The average power densities （ repetition frequency pulse wide） of which were 10 mW/cm2 （100 pps 500 MS）, 30 mW/cm2 （300 pps 500 MS） and 30 mW/cm2 （1000 pps 150 MS）. At 6th hour after irradiation, flow cytometry was used to detect the cell cycle, ratio of apoptosis and necrosis; laser confocal microscopy was used to observe the apoptosis and necrosis;transmission electron microscopy was applied to observe the uhrastructural changes of the cells. Results After 10 mW/cm2 （100 pps 500 MS） irradiation, the number of cells in Go -G1 phase wassignificantly decreased （P 〈0. 05）, those in G2 -M phase were increased （P 〈0.01）. After 30 mW/cm2（1000 pps 150 MS） irradiation, the number of cellsin GO - G1 phase was increased （ P 〈 0. 05 ）, those in G2-M phase were decreased （ P 〈 0. 01 ）. After 30 mW/cm2 （300 pps 500 MS） irradiation, the number of cellsin Go - G1 phase was increased （P 〈 0. 05 ）, those in S phase were decreased （ P 〈 0. 01 ）. The ratio of apoptotic cells was increased （ P 〈 0. 01 ）. Uhrastructure of PC12 cells showed dilatation of perinuclear space, condensation and margination of nuclear chromatin, nucleoli became honeycomb appearance, and swelling and vacuolization of mitochondri- a. Conclusion 30 mW/cm2 （300 pps 500 MS） microwave irradiation for 5 minutes can induce growth inhi- bition, increased apoptosis and structural injury of PC12 cells, and this dosage may be used for studies of the mechanism of microwave radiation.