A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion
A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion
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DOI：
10.3791/3896
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发表时间：
2012-07-01
影响因子：
1.2
通讯作者：
Baumgarten, Georg
中科院分区：
文献类型：
--
作者：
Kim, Se-Chan;Boehm, Olaf;Baumgarten, Georg
在开胸冠状动脉结扎模型中，开胸手术创伤诱导了免疫应答，该免疫应答改变了涉及缺血和再灌注的不同机制。免疫应答包括细胞因子表达和先天免疫受体的内源性配体的释放或分泌。先天免疫的激活可以潜在地调节梗死面积。我们已经修改了现有的小鼠闭胸模型，悬挂重量，这可能是有用的研究心肌预处理和后处理和先天免疫在心肌缺血和再灌注的作用。该模型允许动物在心肌缺血发作前从手术创伤中恢复。挥发性麻醉剂已被深入研究，其对缺血心脏的预处理作用是众所周知的。然而，这种保护作用排除了其在冠状动脉结扎的开胸模型中的使用。因此，另一个优点可能是在慢性闭胸模型中使用可控性良好的挥发性麻醉剂用于仪器，因为它们的预处理效果持续长达72小时。该模型还可用于慢性心脏病间歇性缺血模型和多次打击模型。在识别左前降支后，将结扎线穿过血管下方，并将缝线两端穿过封堵器。然后，缝线两端穿过胸壁，打结形成一个环并留在皮下组织中。在胸部闭合和恢复5天后，再次麻醉小鼠，重新打开胸部皮肤，并在ECG控制下将悬挂重物连接到环上。在缺血/再灌注方案结束时，心脏可以用TTC染色以评估梗死面积或进行灌注固定以允许除了组织学和免疫组织化学之外的形态测定研究。
Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ischemia and reperfusion. Immune response includes cytokine expression and release or secretion of endogenous ligands of innate immune receptors. Activation of innate immunity can potentially modulate infarct size. We have modified an existing murine closed-chest model using hanging weights which could be useful for studying myocardial pre- and postconditioning and the role of innate immunity in myocardial ischemia and reperfusion. This model allows animals to recover from surgical trauma before onset of myocardial ischemia.Volatile anesthetics have been intensely studied and their preconditioning effect for the ischemic heart is well known. However, this protective effect precludes its use in open chest models of coronary artery ligation. Thus, another advantage could be the use of the well controllable volatile anesthetics for instrumentation in a chronic closed-chest model, since their preconditioning effect lasts up to 72 hours. Chronic heart diseases with intermittent ischemia and multiple hit models are other possible applications of this model.For the chronic closed-chest model, intubated and ventilated mice undergo a lateral blunt thoracotomy via the 4th intercostal space. Following identification of the left anterior descending a ligature is passed underneath the vessel and both suture ends are threaded through an occluder. Then, both suture ends are passed through the chest wall, knotted to form a loop and left in the subcutaneous tissue. After chest closure and recovery for 5 days, mice are anesthetized again, chest skin is reopened and hanging weights are hooked up to the loop under ECG control.At the end of the ischemia/reperfusion protocol, hearts can be stained with TTC for infarct size assessment or undergo perfusion fixation to allow morphometric studies in addition to histology and immunohistochemistry.