靶向超声微泡造影剂对犬缺血再灌注心肌的延迟显像研究

目的用自制的靶向超声微泡造影剂,实现无创性地评价犬心肌缺血再灌注(I-R)的范围及严重程度.方法将本研究所自行研制的表面活性剂类超声造影剂--"表活显"表面,结合上磷脂酰丝氨酸(PS),制备成具有靶向性的造影剂(MB-PS),用MB-PS对犬I-R模型在实时心脏超声造影条件下进行延迟心肌显像,实验结束后,心肌经0.5%伊文思蓝(Evens)和1%氯化三苯四氮唑(TTC)染色,确定缺血及坏死心肌范围,并与延迟心脏超声造影显像结果比较其一致性.结果细胞流式术(FC)证明了PS结合在造影剂微泡的表面,延迟心肌显像表明缺血再灌注区的造影剂回声较正常区的回声明显增强,与病理染色结果基本一致.结论缺血损伤再灌注后,心肌缺血部位的造影剂回声较其余部位正常心肌的造影剂回声明显增强,正是因为 MB-PS聚集并停留在缺血-再灌注区,才使得超声可以发现微泡的回声,从而得以无创性地评价炎症发生的部位及其严重程度.

Delayed myocardium contrast echocardiography imaging of ischemia-reperfusion using targeted ultrasound contrast agent

Objective To assess the area and severity of myocardium ischemia-reperfusion injury by noninvasive ultrasound imaging using self-made targeted ultrasound contrast agent. Methods We incorporated the phosphatidylserine (PS) into the shell of the self-made, surfactant fluorocarbon-filled contrast agent for targeted ultrasound contrast agent (MB-PS). Nine open-chest canine myocardium ischemia-reperfusion models were established. Delayed myocardium contrast echocardiography imaging was applied by real-time myocardium contrast echocardiography (MCE) using MB-PS. The region of ischemia and infarction myocardium was identified by 0.5% Evens and 1% TTC dying and compared with delayed MCE imaging. Results Flow cytometry (FC) demontrasted the corporation of PS into the shell of microbubble. Delayed MCE imaging indicated that the acoustic density of ischemia-reperfusion myocardium was significantly increased than other normal myocardium. That was in accord with the result of pathology dying. Conclusion The higher acoustic density was due to MB-PS acculumating and remaining in the I-R region that made the echo of microbubbles was accepted by ultrasound. So, we can noninvasively assess the region and severity of inflammation.