五味子乙素促进心肌梗死小鼠心功能的研究

发布时间：2018-03-23 08:43

本文选题：C57BL/6J小鼠　切入点：心肌梗死模型　出处：《南京医科大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的：建立可靠、稳定的C57BL/6J小鼠缺血性心肌梗死模型,为研究药物治疗心肌梗死的机制奠定基础。方法：C57BL/6J小鼠经4-6小时禁食禁饮,以戊巴比妥钠麻醉后,仰卧固定于手术台,经口气管插管,连接呼吸机,逐层分离胸部皮肤、皮下组织及肌肉,暴露心脏,于左心耳下方2～3毫米处结扎冠状动脉。手术成功标准包括(1)结扎后心肌肉眼观局部苍白,心电图示ST段抬高；(2)术后2天内心脏超声示小鼠左室射血分数下降并小于50%。结果：所有的C57BL/6J小鼠经结扎手术均被成功制作成心肌梗死模型。所有C57BL/6J小鼠心肌梗死后3周内都发生心肌重构,心脏超声示小鼠左室射血分数等指标进行性下降,心腔扩大,室壁变薄,部分小鼠心肌梗死后死亡。结论：经开胸冠状动脉结扎手术是一种稳定、可靠并且能够广泛应用的制作缺血性心肌梗死模型的手段。用小鼠心肌梗死模型来研究药物对心肌梗死后的治疗机制是一种简单、可靠、方便、实用的方法。目的：探讨五味子乙素是否能够改善心梗小鼠心功能及其机制的研究。方法：C57BL/6J小鼠经冠状动脉结扎术后分为三组：假手术组(n=10)；心梗未治疗组(n=20)；五味子乙素治疗组(n=20,五味子乙素80mg/kg/day灌胃),并且在手术后持续给予3周。手术后三周观察各组小鼠生存率,通过二维超声心动图检测心功能各项指标,处死小鼠计算心脏体重比、肺脏体重比,通过Evans蓝和TTC染色计算心梗面积,制作心脏病理切片进行HE染色以及Masson染色。通过免疫荧光方法检测缺血组织中TUNEL、BrdU的表达。通过ELISA方法检测]TNF-α、TGF-β1、IL-1β的表达,Western Blot方法检测NF-κB,Bax,Bcl-2, eNOS,phospho-eNOS,GATA4蛋白的表达。同时培育H9c2心肌细胞,给予五味子乙素预处理后置于缺血缺氧环境,验证该药物在细胞水平上的作用,以及这些作用的药物剂量依赖性。结果：相比心梗未治疗组,五味子乙素治疗组心梗小鼠的死亡率在明显降低。五味子乙素治疗能够改善心梗小鼠的心功能,提高LVEF,LVFS等心功能指标,并对假手术小鼠的心功能不产生影响。五味子乙素治疗能够减少心梗小鼠的心脏梗死面积,降低TNF-α、TGF-β1、IL-1β、NF-κB等炎性因子的表达,而且能够明显地活化内皮一氧化氮合成酶,通过上调Bcl-2/Bax抑制缺血心肌细胞的凋亡,并且具有一定的心肌修复能力。结论：心肌梗死对小鼠的缺血心肌细胞产生炎症、纤维化、凋亡的作用。五味子乙素治疗能够明显改善心梗小鼠的心脏功能,延缓心肌重构,减少心脏梗死面积,改善缺血心肌细胞的炎症、纤维化、凋亡作用,加强缺血心肌细胞的修复,从而提高心梗小鼠的生存率。
[Abstract]:Aim: to establish a reliable and stable model of ischemic myocardial infarction in C57BL/6J mice. Methods after 4-6 hours fasting, the mice were anesthetized with pentobarbital sodium and fixed on the operating table. The mice were intubated with oral tube and connected to the ventilator. The chest skin, subcutaneous tissue and muscle were separated layer by layer to expose the heart. Coronary artery was ligated at 2mm below the left atrial appendage. The successful criteria included 1) local paleness of cardiac muscle eye after ligation, and ECG showed St segment elevation 2) the left ventricular ejection fraction was decreased and less than 50% by echocardiography within 2 days after operation. Results: all C57BL/6J mice were successfully made into myocardial infarction model by ligation. Myocardial remodeling occurred in all C57BL/6J mice within 3 weeks after myocardial infarction. The left ventricular ejection fraction was decreased and the heart cavity was enlarged by echocardiography. The wall became thinner and some mice died after myocardial infarction. Conclusion: transthoracic coronary artery ligation is a stable procedure. It is a simple, reliable, convenient and practical method to study the mechanism of treatment after myocardial infarction by using mouse myocardial infarction model. Aim: to investigate whether Schisandrin B can improve cardiac function and its mechanism in myocardial infarction mice. Methods: C57BL / 6J mice were divided into three groups after coronary artery ligation: sham operation group (n = 10), myocardial infarction group (n = 20), Schisandrin B group (n = 20) and Schisandrin B (80mg/kg/day) administered intragastrically for 3 weeks. Survival rate of mice in each group, The indexes of cardiac function were measured by two-dimensional echocardiography. The heart weight ratio, lung weight ratio and myocardial infarction area were calculated by Evans blue and TTC staining. The expression of Tunel BrdU in ischemic tissue was detected by immunofluorescence method. The expression of TNF- 伪 TGF- 尾 1 尾 IL-1 尾 was detected by ELISA method. The expression of NF- 魏 B Baxon Bcl-2, eNOSphospho-eNOSGATA4 protein was detected by Western Blot. Schisandrin was pretreated with Schisandrin in ischemic and hypoxic environment to verify the effect of Schisandrin on cell level and its dose-dependent effects. Results: compared with untreated myocardial infarction group, the mortality of myocardial infarction mice in Schisandra B treatment group was significantly decreased, and Schisandrin B treatment could improve cardiac function and increase LVEFV LVFS in myocardial infarction mice. Schisandra B can reduce the infarct size of heart, decrease the expression of inflammatory factors such as TNF- 伪, TGF- 尾 1, IL-1 尾 and NF- 魏 B, and activate endothelial nitric oxide synthase. Up-regulation of Bcl-2/Bax inhibits apoptosis of ischemic cardiomyocytes and has certain ability of myocardial repair. Conclusion: myocardial infarction can induce inflammation, fibrosis and apoptosis in ischemic cardiomyocytes of mice. Schisandra B can obviously improve heart function, delay myocardial remodeling and reduce infarct size in myocardial infarction mice. Improve the inflammation, fibrosis, apoptosis of ischemic cardiomyocytes, strengthen the repair of ischemic cardiomyocytes, thus improve the survival rate of myocardial infarction mice.
【学位授予单位】：南京医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R285.5

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