超声微泡造影剂对心肌组织的生物学效应及介导VEGF基因转染大鼠心肌的实验研究

Experimental Study on Ultrasound-Mediated Microbubble Destruction Deliver VEGF Gene to Myocardium of Rats and Its Biological Effects

目的 探讨超声微泡造影剂对心肌组织的生物学效应及其介导VEGF基因转染大鼠心肌的有效性。方法 18只健康雄性Wistar大鼠 ,取 3只采用超声波在鼠胸壁破坏微泡造影剂 ,观察对心肌组织显微结构的影响。将另 15只急性心肌梗死 3天后的雄性Wistar大鼠分为 3组 ,每组 5只。第一组采用超声破坏微泡造影剂的方式 ,将pcD2 VEGF12 1基因转染大鼠心肌至造影剂不再显影 (约 6min) ;第二组尾静脉输入同等剂量携pcD2 VEGF12 1基因的造影剂 ;第三组为对照。 2周后 ,取缺血心肌组织行VEGF免疫组织化学染色 ,观察心肌组织血管内皮生长因子 (VEGF)蛋白表达情况。结果 超声波破坏微泡造影剂能使心肌组织充血 ,产生大量空泡 ,并有部分心肌细胞坏死。采用超声微泡造影剂介导的VEGF基因转染 ,能明显增强大鼠心肌组织VEGF蛋白的表达。结论 超声微泡造影剂能明显增强对组织的空化效应 ,其介导的VEGF基因治疗是一种无创、新型、高效的基因转移方法。

Objective To investigate whether ultrasound mediated microbubble destruction could be effectively deliver vascular endothelial growth factor (VEGF) gene to myocardium of rats and its biological effects.MethodsEighteen male Wistar rats were included in this study. Three of them were subject to ultrasound irradiation through the chest wall with simultaneous intravenous administration contrast microbubble (QuanFuXian), tissueslices of the heart were collected for microscope investigation. The remaining fifteen rats were subjected to left anterior descending coronary artery ligation. Three days after surgery, the rats were divided into 3 groups. Microbubbles attached with pcD 2VEGF 121 gene were infused into the tail vein of rats with or without simultaneous echocardiographic destruction microbubbles. The third group used as control group. Rats were killed after 2 weeks and examined for VEGF protein expression by immunohistochemical technique. Results Microscope findings showed that myocardium tissue conducted with ultrasound mediated microbubble destruction became congestive, lots of gas bubbles were seen in it, and myocardiolysis was seen in parts of the heart tissue. VEGF protein expression was higher in ischemic myocardium of rats received ultrasound mediated microbubble destruction for gene delivery than in ischemic myocardium of rats in the controls. Conclusion Ultrasound contrast agents lower the threshold for cavitation by ultrasound energy. Ultrasound microbubbles may de used as cavitation nuclei for drug and gene delivery. Ultrasound mediated microbubble destruction is a promising method for noninvasive and effective delivery targets genes to the heart. [