中文摘要：

目的探讨高强度皮秒脉冲电场对人宫颈癌HeLa细胞的体外损伤效应及机制。方法固定皮秒脉冲电场脉宽800ps、频率3Hz、场强250kV／cm，根据处理脉冲个数不同（0、1000、3000和5000个），将HeLa细胞分为对照组和不同剂量皮秒脉冲处理组，通过MTT比色法检测皮秒脉冲对各组细胞在处理后不同时间点生长抑制的影响；Fluo—s／AM探针标记细胞，激光扫描共聚焦显微镜检测细胞[-Ca抖Ji改变；Westernblot法检测皮秒脉冲电场作用后Bax／Bcl-2蛋白表达量的改变。结果随着脉冲剂量的增加，细胞死亡率上升，生长受到抑制，12h时抑制率最为显著；皮秒脉冲处理可明显升高细胞[-Ca^2＋]i（P〈0．05）；随着脉冲剂量的增加，细胞内Bax蛋白表达量由对照组的0．205±0．102增加至各处理组的0．257±0．083、0．586±0．138和0．791±0．262（P〈0．05）；Bcl-2蛋白表达量由对照组的0．694±0．132降低至各处理组的0．591±0．145、0．364±0．105和0．262±0．092（P〈0．05）；Bax／Bcl-2比值显著上调（P〈0．05）。结论高强度皮秒脉冲电场对HeLa细胞有损伤效应，并能诱导其凋亡。

英文摘要：

Objective To investigate the damaging effect and mechanism of intense picosecond pulsed electric field （psPEF） on HeLa ceils in vitro. Methods Intense psPEF with constant parameters （pulse duration of 800 ps,repetition frequency of 3 Hz,and electric intensity of 250 kV/cm） and different pulses （0,1 000,3 000 and 5 000） were performed on HeLa cells. MTT assay was used to trace the effect of growth inhibition at different times. The changes of [Ca2＋ ]i in HeLa cells were observed by laser scan- ning confocal microscope using Fluo-3/AM as the calcium fluorescent indicator. Western blot was used to measure the changes of expression level of Bcl-2 and Bax. Results The mortality rate of HeLa cells elevated with increasing of the amount of pulses,and the maximum inhibitory rate was observed 12 h after the treatment. Compare with the control group, [Ca^2＋ ]i was markedly in- creased by treatment with psPEF （P〈0.05）. By increasing the pulse number, the expression of Bax was increased from 0. 205 ± 0. 102 in control group to 0. 257J：：0. 083,0. 586~0. 138 and 0. 791＋_0. 262 in treated groups （P~0.05） ,and Bcl-2 was decreased from 0. 694±0. 132 in control group to 0. 591±0. 145,0. 364±0. 105 and 0. 262±0. 092 in treated groups （P〈0.05） ,demonstra- ting significant increase of Bax/Bcl-2 ratio in all treated groups （P〈0.05）. Conclusion Intense psPEF can damage the HeLa cells as well as inducing tumor cell apoptosis.