微波辐射致大鼠PC12细胞损伤作用

Influence of microwave radiation on PC12 cells

目的观察微波辐射后大鼠肾上腺嗜铬细胞瘤细胞系(PC12)细胞形态、超微结构、周期和凋亡等变化,以探讨微波辐射对其影响。方法PC12细胞传代培养,6～7 d细胞处于对数生长期后,神经生长因子(NGF)诱导7～10 d,分别采用0,10,30和50mW/cm2微波辐射,于辐射后6 h和1 d收集细胞,利用原子力显微镜、透射电镜、流式细胞仪和激光共聚焦扫描显微镜等技术,研究PC12细胞膜、超微结构、细胞周期及细胞坏死和凋亡的变化。结果辐射后G0-G1期细胞数增加,以30和50 mW/cm2为明显,10 mW/cm2组未见明显改变。30 mW/cm2组PC12细胞凋亡率升高(P<0.01),坏死率无明显改变;细胞核膜间隙增宽,染色质浓缩边集,核型不整,线粒体肿胀空化,内质网扩张;细胞膜表面粗糙,见圆形或不规则形穿孔。结论30mW/cm2微波辐射可使PC12细胞损伤,表现为细胞周期阻滞、凋亡增加、超微结构改变及膜穿孔。

Objective To investigate the changes of cell membrane, ultrastructure, cell cycle and the apoptosis rate in PC12 cells after microwave radiation. Methods The PC12 cells in logarithmic growth period of 6- 7 d were induced with nerve growth factor for 7 - 10 d. Then the cells were exposed tmo microwave at average power densities of 0, 10, 30 and 50mW/c^2 respectively. The PC12 cell membrane, ultrastructure, cell cycle and the apoptosis rate were studied by means of atomic force microscope, transmission electron microscope, flow cytometry and laser scanning confocal microscope. Results After 30 and 50 mW/em2 microwave exposure, there were more cells in Go - GI phase and no change after exposure to 10 mW/cm2 radition. In the 30 mW/cm2 group, apoptosis rate was significantly higher （ P 〈 0.01 ） and necrosis rate was no change. Cells with the irregular nucleus, chromatin concentration, nucleus intermembrance space widen, mitochondria swelling and cavitation, rough endoplasmic reticulum expanding were observed. The membrane of PC12 cells was rough and there were some round or irregular holes. Conclusion 30 mW/cm2 microwave radiation may induced PC12 cell injury, cause the blockage of cell cycles, cell apop.tosis, the abnormal ultrastructure and membrane perforation.