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目的:微创条件下建立小鼠慢性心肌梗死模型,为研究干细胞移植治疗对心肌梗死后心脏的影响提供模型。方法:将70只小鼠随机分为6组,5个手术组和1个假手术组。手术组小鼠于左侧胸骨旁0.8 cm处切开一长约1 cm的切口,钝性分离暴露肋间隙。将心脏从第4、5肋间隙挤出,用5号丝线结扎左心耳和动脉圆锥下的左前降支,放回胸腔后缝合胸壁皮肤。假手术组小鼠左前降支动脉不结扎,余操作同手术组。观察手术后心脏大体形态,术后30 min、3、5、7、14和21 d的心电图及心脏组织的病理学变化。结果:左心室梗死区呈暗褐色,经固定液灌流后梗死区呈白色透明状。术后30 min内,心电图上ST段弓背向上抬高超过0.2 mV。术后3、5、7、14和21 d,心电图被病理性Q波代替,ST段低平。苏木精-伊红染色显示,术后3、5 d有大量的炎细胞浸润,心肌细胞不完整,以术后5 d更明显。术后7 d、14 d梗死区心肌纤维断裂溶解,心肌细胞坏死,少量炎性细胞浸润,术后21 d梗死区被纤维组织所代替。结论:以微创手术建立小鼠心肌梗死模型为一种渐进性、慢性过程,该方法操作时间短、动物耐受性好、可重复性强。
OBJECTIVE: To establish a mouse model of chronic myocardial infarction under minimally invasive conditions and to provide a model for studying the effects of stem cell transplantation on the heart after myocardial infarction. Methods: Seventy mice were randomly divided into 6 groups, 5 surgery groups and 1 sham operation group. The mice in the operation group were incised for a length of about 1 cm at 0.8 cm beside the left sternum, and blunt dissection revealed the intercostal space. The heart out from the 4,5 intercostal space, with 5 thread ligation of the left atrial appendage and the left anterior descending artery under the conus, back into the chest after suture the chest wall skin. Sham-operated mice left anterior descending artery was not ligated, more than the same operation with the operation group. The gross morphology of the heart after operation, electrocardiogram and cardiac pathological changes at 3, 5, 7, 14 and 21 days after operation were observed. Results: The area of left ventricular infarction was dark brown, and the infarct area was white and transparent after perfused with fixed fluid. Within 30 minutes after surgery, the ST segment of the ST elevation on the electrocardiogram rose more than 0.2 mV. At 3, 5, 7, 14 and 21 days after operation, the electrocardiogram was replaced by pathological Q wave and ST segment was flat. Hematoxylin-eosin staining showed that a large number of inflammatory cells infiltrated 3 and 5 days after operation, and myocardial cells were incomplete, which was more obvious on the 5th postoperative day. At the 7th day and the 14th day after myocardial infarction, the myocardial fibers were lysed, the myocardial cells were necrotic, a small amount of inflammatory cells infiltrated, and the infarcted area was replaced by fibrous tissue 21 days after operation. Conclusion: The minimally invasive myocardial infarction model in mice is a progressive and chronic process. The method has short operation time, good animal tolerance and strong repeatability.