【摘要】 目的　研究超声破坏微泡造影剂对靶区内心肌组织毛细血管通透性的影响 ;探讨超声微泡造影剂增强基因转染的机制。方法　 2 4只健康雄性 Wistar大鼠 ,取 15只分为 3组 ,第 1组经静脉输入含有伊文思蓝 (Evans blue,EB)的微泡造影剂 ,并采用超声波在鼠胸壁辐照约 6 min破坏心肌组织内造影剂 ;第 2组采用超声照射 ,同时经静脉单纯输入 EB溶液 ;第 3组单纯经静脉输入 EB作为对照。照射完毕 2 h后放血处死大鼠 ,使用标准曲线和分光光度法测量各组大鼠心肌组织中 EB含量 (作为反映血管通透性的指标 )。另 9只大鼠随机分为 3组 ,每组 3只。第 1组经静脉输入微泡造影剂 ,并采用超声波在鼠胸壁辐照约 6 min破坏心肌组织内造影剂 ;第 2组单纯采用超声照射 ;第 3组不加任何处理 ,作为对照。照射完毕即刻处死大鼠 ,取心肌组织进行电镜观察毛细血管的改变。结果　采用超声照射 ,并经静脉输入微泡造影剂的大鼠 ,心肌组织中 EB含量为 (75 .33± 16 .80 )μg/ g,比单纯超声照射[(32 .2 1± 9.5 3)μg/ g]及心肌正常组织 EB含量 [(37.16± 7.98)μg/ g]明显增加 (P<0 .0 5 )。电镜结果显示超声破坏微泡后 ,能使毛细血管破裂 ,红细胞溢出于毛细血管外。结论　超声波触发破坏微泡造影剂后能使心肌组织毛细血管通透性增加 ,可更多还原

【Abstract】 Objective To investigate the destructive effects of ultrasound mediated microbubbles on vascular permeability in myocardium.Methods Twenty four male Wistar rats(average weight 280±35 g)were included in this study.Fifteen of them were randomly divided into 3 groups:Group one:The rats were irradiated with US for six min through the chest wall and were simultaneously intravenously administrated 3% Evans blue(30 mg/kg)with contrast microbubbles(Quan fuxian);Group two:The rats were intravenously administered Evans blue to detect vascular permeability of myocardium together with ultrasound irradiation.Group 3:The rats were simply administered EB two hours after ultrasound irradiation and the rats were killed through bleeding.The contents of Evans blue in the heart tissues of the three groups,which were used as the indices of vascular permeability,were calculated by the standard curve and spectrophotometry.The remaining nine rats were randomly divided into 3 groups.Group one:The rats underwent US irradiation through the chest wall together with simultaneous intravenous administration of contrast microbubbles.Group 2:the rats were only irradiated with ultrasound.Group 3:The rats were used only as controls without treatment.After ultrasound irradiation,tissue slices of the heart of the killed rdts were collected for transmission electron microscopic investigation.Results The Evans blue contents in the rat heart tissue conducted by ultrasound irradiation with microbubble administration were two-fold higher than those of the other two groups(P<0.05).With transmission electron microscopic investigation,we found red blood cells oozed from the capillaries in rats of ultrasound mediated microbubble destruction group.Conclusions Simultaneous exposure of rat hearts to ultrasound and contrast agents would result in increase of vascular permeability.It may be one of the mechanisms for gene delivery by ultrasound contrast agents.更多还原