超声破坏微泡对心肌细胞膜通透性影响的研究

目的探讨超声破坏微泡造影剂对心肌细胞膜通透性的影响。方法将15只昆明小白鼠随机分为3组,一组采用尾静脉输入白蛋白微泡造影剂,胸壁用频率为1MHz,强度为1.5W/cm2的超声进行辐照1min;一组单纯采用同等超声辐照相同时间;一组作为对照。作用后即刻取心肌组织用硝酸镧(La)示踪法做透射电镜观察心肌细胞膜通透性的变化。结果采用超声破坏微泡后可见部分镧颗粒分布于心肌细胞胞浆内,部分分布于线粒体外、细胞核外;单纯超声作用组心肌细胞胞浆中可有少量的镧颗粒分布,而大部分镧颗粒分布于细胞膜外;而对照组镧颗粒分布于心肌细胞膜外。结论超声破坏微泡可提高心肌细胞膜通透性,可能是超声微泡造影剂增强组织中基因转染的机制之一。

Effect of Ultrasound-mediated Microbubble Destruction on Permeability of Myocardial Cell Membrane

Objective To investigate the effect of ultrasound-mediated microbubble destruction on the permeability of myocardial cell membrane. Methods Fifteen Kunming mice were randomly dividedd into 3 groups. In group one, after injection of ultrasound contrast agent, ultrasound with the frequency of 1 MHz, and the intensity of 1.5 W/cm^2 was applied on the chest of the mice. In group two, ultrasound irridiation was simply used on the mice ; the third group was the control group. Immediately after the treatment, the mice were killed and the myocardium was harvested for electron microscope examination by means of La tracer. Results In group one, many particles of La were seen in the cells ; in group two, little La particles were seen in the cells, most of the particles were seen outside of the cells ; while in group three,no La particle appeared in the cells. Conclusions Ultrasound-mediated microbubble destruction could enhance the permeability of myocardial cell membrane. This might be one mechanism for gene delivery with microbubbles.