一种快捷小鼠心肌梗死模型的建立

目的建立一种快速高效不需要通气辅助呼吸的小鼠心肌梗死模型制作方法,并对制作过程中的技巧细节进行分析。方法 40只C57/B6雄性小鼠,随机分成手术组(25只)和对照组(15只),于麻醉状态下在左侧第3,4肋间隙挤出心脏,手术组结扎冠状动脉左前降支建立小鼠心肌梗死模型;对照组不结扎冠状动脉,其余操作与手术组相同。28天后,心脏超声系统进行心功能测定对比,解剖进行形态对比和病理染色对比心肌梗死和纤维化。结果至术后第28天,手术组心肌梗死小鼠的生存率80%,对照组的小鼠生存率100%。超声检测显示28天后手术组小鼠心功能明显降低,与对照组相比,手术组心室明显扩大,左心室舒张期末内径由3.52±0.10 mm扩大到4.65±0.08 mm(P<0.0001),左心室收缩期末内径由2.60±0.19 mm扩大到4.36±0.13 mm(P<0.0001);左心室射血分数由66.70%±1.41%下降到29.70%±1.64%(P<0.0001),左心室缩短分数由35.90%±1.01%下降到14.20%±0.80%(P<0.0001)。肉眼可见手术组小鼠心脏左心室心腔变大,心室壁明显变薄,梗死面积可达45.10%±1.53%;HE、免疫组织化学、Masson病理染色可见有明显纤维瘢痕形成,有大量炎细胞浸润。结论此种方法制备心肌梗死模型高效快捷,动物死亡率低,结果明显,是一种较好的方法。

Establishment of Murine Model of Myocardial Infarction by a Rapid and Efficient Procedure

Aim To introduce a rapid and efficient model of myocardial infarction(MI) without the requirement of ventilation in the mouse and comprehensively describe its details.Methods 40 Male BABL/C6 mice were divided into 2 groups: new method MI(15) and new method Sham(25).In the new method,hearts of total 40 mice were manually exposed through a small incision of the left fourth intercostal space without intubation.In group of MI,the left anterior descending coronary artery was ligated.Hearts from group of Sham were without ligation.This novel MI procedure is rapid,with an average procedure time of 60±15 seconds.We compared the difference between MI and Sham post 28days with analysis of echocardiography,morphology and pathology.Results Survival rate of group MI was 80% and group Sham was 100% 28 days after surgery with our method.The echocardiography showed that the heart function of the mice with 28-day post-MI was markedly impaired.The LVIDd and LVIDs were significantly increased from 3.52±0.10 mm and 2.60±0.19 mm to 4.65±0.08 mm and 4.36±0.13 mm(P< 0.0001),while LVEF and LVFS were decreased significantly 66.70%±1.41% and 35.90%±1.01% vs 29.70%±1.64% and 14.20%±0.80%,P<0.0001,respectively.Anatomical analysis of hearts with 28-day post-MI showed enlarged left ventricles and thin ventricular walls.The infarct size reached to 45.10%±1.53%.Hematoxylin eosin(HE),Immunohistochemistry(IHC) and masson trichrome(Masson) staining confirmed plenty of macrophages infiltration and fibrosis formation.Conclusion This new rapid method of MI in mice represents a more efficient model of myocardial ischemic injury.