中文摘要：

目的：研究低频超声联合微泡剂对肝癌细胞SMMC-7721的作用，为超声治疗的临床应用提供实验依据。方法：将细胞分为空白对照（A）组、单纯微泡剂（B）组、单纯超声（C）组和超声联合微泡剂（D）组。再按超声辐照60、90、120和150s，C组分为C1、C2、C3、C4，D组分为D1、D2、D3、D4。MTT法观察细胞增殖的抑制作用；分光光度法检测细胞培养液中活性氧（ROS）和超氧化物歧化酶（SOD）活力的变化，流式细胞仪（FCM）检测细胞凋亡。结果：超声联合微泡剂能够显著抑制细胞增殖；C3、D3组培养液中ROS活力显著高于A、B两组（P〈0．01），SOD活力明显低于A、B两组（P〈0．01），且D3组效应比C3组更为明显；C3、D3组细胞凋亡率明显高于A、B组（P〈0．01），D3组高于C3组（P〈0．05）。结论：低频超声联合微泡剂可能是通过增加细胞外ROS的活力来诱导对细胞的损伤和凋亡。

英文摘要：

Objective To observe the bio-effects of SMMC-7721 cells treated with low-frequency ultrasound and microbubble agent to offer the clinic application theory basis of ultrasound. Methods Cells were divided into four groups ： A, control; B, pure microbubble agent; C,pure ultrasound, according to the exposure time, group C was subdivided to C1 （exposed for 60 s）, C2（exposed for 90 s）, C3（exposed for 120 s） and C4（exposed for 150 s） ; D, lowfrequency ultrasound combined with microbubble agent, according to the exposure time,group D was subdivided to D1 （exposed for 60 s）, D2（exposed for 90 s）, D3（exposed for 120 s） and D4 （exposed for 150 s）. The survival rate of VEC-30d cells was observed by MTT colorimetric assay. Visible spectrophotometric was applied to determine ROS and SOD . Cell apoptosis was analyzed using flow cytometry after ultrasonic exposure . Results Group C and D were obviously inhibited to proliferated, as observed by MTT colorimetric assay. The yield of ROS of group C3 and D3 was much higher than that of group A,B and the yield of SOD of group C3 and D3 was much lower than that of group A ,B. The apoptosis rate was found to reach （ 15.24 ± 2.16） % in group C3 and （27.31 ± 4.14） % in group D3 with FCM. Conclusions Low-frequency ultrasound combined with micro-bubble agent can induce injury and apoptosis of SMMC-7721 cells, probably due to the increase of the activity of ROS in cultured liquid.