中文摘要：

【目的】探讨小鼠急性心肌梗死后消化道不同肠段通透性的变化。【方法】61只雄性C57BL/6小鼠随机分为正常对照组（n=18）、假手术组（n=18）和急性心肌梗死组（n=25）。急性心肌梗死组采用左冠状动脉前降支结扎法制备小鼠急性心肌梗死模型,假手术组行相同操作,但不结扎左冠状动脉前降支。急性心肌梗死后第3天高频小动物超声影像系统评价小鼠心功能,异硫氰酸荧光标记的右旋糖酐（fluorescein isothiocyanate-dextran,FD4）法分别检测远端小肠、盲肠和结肠的肠道通透性,HE染色观察远端小肠、盲肠和结肠的组织病理学变化,TTC染色评价小鼠心脏梗死面积。【结果】小鼠急性心肌梗死模型建立成功率为72%（18/25）。急性心肌梗死组小鼠术后左心室舒张末期内径（4.72±0.22）mm和左心室收缩末期内径（3.89±0.28）mm明显高于正常对照组和假手术组（P〈0.05）,射血分数（32.59±2.52）%和短轴缩短率（15.57±1.25）%明显低于正常对照组和假手术组（P〈0.0001）。急性心肌梗死组小鼠远端小肠（9.76±0.78）μg/ml、盲肠（1.82±0.21）μg/ml和结肠（5.41±0.84）μg/ml的通透性均明显高于正常对照组和假手术组（P〈0.0001）,且远端小肠、盲肠和结肠的肠黏膜组织伴炎性水肿。【结论】小鼠急性心肌梗死后远端小肠、盲肠和结肠通透性均增加,且盲肠的肠道通透性最显著、其次是结肠和远端小肠。

英文摘要：

【Objective】To explore the changes of gut permeability in different intestinal segments of mice after acute myocardial infarction.【Methods】A total of 61 male C57BL/6 mice were randomly divided into normal control group（n=18）, sham operation group（n=18） and acute myocardial infarction（MI） group（n=25）. Mouse models in MI group were made via ligating the left anterior descending coronary artery. Mice in sham operation group underwent similar procedure except for coronary artery ligation. High frequency ultrasound imaging system was used to evaluate the cardiac functions of mice on the 3rd day after acute MI. Gut permeability of distal small intestine, cecum and colon was detected with fluorescein isothiocyanate-dextran（FD4） method. The pathological changes of intestinal mucosa in distal small intestine, cecum and colon were observed with hematoxylin and eosin staining. MI area was assessed with 2,3,5-triphenyl tetrazolium chloride（TTC） staining.【Results】Acute MI was successfully induced in 72% mice（18/25）. Left ventricular（LV） end diastolic diameters（4.72 ± 0.22）mm and LV end systolic diameters（3.89±0.28）mm of postoperative mice in MI group were significantly higher than those in normal control group and sham operation group（P0.05）, while ejection fraction（32.59±2.52）% and fractional shortening（15.57 ± 1.25）% were obviously lower than those in the other two groups（P0.0001）. Compared with急性心肌梗死（acute myocardial infarction,AMI）normal control group and sham operation group, gut permeability of distal small intestine（9.76±0.78） μg/ml, cecum（1.82±0.21）μg/ml and colon（5.41±0.84） μg/ml in MI group increased significantly（P0.0001）and inflammatory edema appeared in mucosa tissues of those intestinal segments.【Conclusion】Gut permeability increases in distal small intestine, cecum and colon of mice after acute MI.Permeability of cecum is the most significant, followed by colon and distal small intestine.