The study was supported by the Swiss National Foundation [SNF 310030-149986 to MNG], the University of Fribourg, and Fribourg Hospital.

所有的动物在符合欧洲公约动物保健收到人文关怀。获得国家兽医局，弗里堡，瑞士联邦兽医办公室，瑞士批准同意后按照瑞士动物保护法进行外科手术。 1.心收获注:所有手术干预措施，异氟烷麻醉下进行的。作出了努力，以减少动物的痛苦。特别是，所有动物接受0.1毫克/千克丁丙诺啡预麻醉的皮下注射。外科协议诱导心肌梗塞先前已在别处13中所述。 <ol><li>麻醉（插管动物，2.5％异氟烷麻醉适当通过爪子捏反射确认）下一个的心肌梗死的动物进行胸骨。 <ol><li>通过切割皮肤，然后肌肉打开动物用手术剪。削减左，右肋骨，然后取出胸部。 </li><li>删除以前的手术（LAD结扎）后剩余的粘连。切开主动脉并取出心脏。把在1M氯化钾（在PBS中）的组织，然后用PBS清洗。 </li></ol></li></ol> 2.组织准备<ol><li>把梗死心脏在纵向的丙烯酸大鼠心脏矩阵。保持在-20℃1小时。 </li><li>直接使用具有横向刀片矩阵切心脏。确保每片厚2毫米。切割约5 - 为每个心脏（基于重构级）7滑动;这就是所谓的系统抽样。 </li><li>在此步骤中，执行2,3,5-氯化三苯基四唑（TTC）染色是可选的（保持心脏切片基站至顶点的方向）。 <ol><li>在37℃孵育，在PBS中的1％TTC 50分钟。孵育它在4％低聚甲醛（PFA）进行20分钟至1小时。把部分betweeÑ与2-毫米间隔物的两块玻璃板和拍照与15X放大率耦合有相机的体视显微镜。 警告！多聚甲醛是有毒的。 </li></ol></li><li>幻灯冻结（ 第一选择） <ol><li>把每个幻灯片在塑料模具（10×10×5毫米）的带安装为cryotomy介质（最佳切割温度，OCT）保持取向（放置部的面向顶点侧倒在模具的底部）。冷冻液态氮冷却10下与2-甲基丁烷蒸气块 - 15分钟。最后，保存在-80℃的组织。 </li></ol></li><li>石蜡化（ 第二选项） <ol><li>放置在包埋盒的每个滑板（通过将部分向下在盒的底部的面向顶点侧保持的取向），然后在4％PFA 24小时。把它放在纸巾处理器的机器过夜。 <ol><li>孵育它在乙醇中的70％2小时。孵育它伊桑醇95％2小时。孵育它在乙醇100％，持续3小时。孵育它在二甲苯4小时。孵育它在石蜡（熔融在60℃下在烘箱中）5小时。最后，通过嵌入在石蜡每个心脏幻灯片制作块。 </li></ol></li></ol></li></ol> 3.马森Goldner三色染色<ol><li>使从石蜡块组织切片用手动切片（厚度:5微米），或从OCT块设置为-18℃的低温恒温器（厚度:7微米）。 </li><li>从染色心脏各部分一张幻灯片每只大鼠（3 -每张幻灯片4横向剖面的）用Masson-Goldner三色染色（ 见附件 ）。 注:这一步的石蜡切片开始。 <ol><li>熔化在60℃下将载玻片在烘箱。根据通风橱，deparaffinize它们二甲苯两次，每次10分钟。水化它们在100％乙醇，95％乙醇，70％乙醇和蒸馏水对每个3分钟。 注:从这一步骤的开始冰冻切片秒。 </li><li>解决这些问题的解决方案，布安一夜之间。然后，冲洗他们在流动的自来水10 - 15分钟。冲洗他们在蒸馏水中。孵育他们在Mayer的苏木3分钟。 </li><li>删除的幻灯片，让他们在蒸馏水中5分钟。然后，孵育它们在酸性品红-丽春5分钟。冲洗他们在1％乙酸1分钟。 </li><li>其次，培养他们磷钼酸橙G 1分钟。冲洗他们在1％乙酸，1分钟，孵育它们在光绿色染料10分钟，并冲洗它们在1％乙酸1分钟。 </li><li>脱水它们在70％的乙醇（30秒），95％的乙醇（30秒），和100％的乙醇（5分钟）。放在组织切片的树脂封固剂一滴，用盖玻片覆盖他们，让他们干。 </li></ol></li></ol> 4.梗死大小分析<ol><li>来自再加上相机立体显微镜（放大15倍），每张幻灯片获得一个图像。照片统治者具有相同的设置秒。 </li><li>使用图像分析软件来测量梗塞，隔膜的厚度，左心室（LV）腔区域，该梗塞区域，使用LV组织区域的中间疤痕的厚度。 <ol><li>设定标尺图像（ 图1A）的规模。 <ol><li>点击测量 ，然后选择设置转换系数 。绘制校准栏上的一条线。右键点击图片，然后点击结束校准 。注意栏值，然后单击确定 。 </li></ol></li><li>从染色心脏的图像（ 图1B）的LV。使用多段工具。选择LV逐点，然后右键单击 复制/粘贴的任何地方。 </li><li>采用单段测量工具测量瘢痕及室间隔厚度（ 图1C </st荣&gt;）。 </li><li>自动检测的LV腔，梗塞，以及使用在RGB模式（ 图1D）的自动区域测量工具的LV面积。 <ol><li>点击工具。 仅激活边框和 连续 RGB模式。最后，点击所关注的区域内检测到它。如有必要，使用精密工具。 </li></ol></li></ol></li><li>计算梗塞大小作为梗塞面积与左心室面积的比率。 </li><li>计算膨胀指数如下:[LV腔面积/整个LV面积] / [梗塞厚度/隔膜厚度]，与整个LV区域包括了LV腔和LV组织区域。 </li><li>最后，如下计算每个心脏一个"平均":从幻灯片梗死扩张平均指数] * [梗死幻灯片数/总幻灯片的数量。 </li></ol>

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The authors have nothing to disclose.

该议定书中的关键步骤 纤维组织可在使用心脏收获和图像的系统抽样一种慢性心肌梗死大鼠模型准确地评估分析从基地获得到顶点三色染色组织切片。两个步骤是成功的协议实现尤为重要。首先，对于心脏收获使用氯化钾使心肌以松弛状态被维持。本步骤是从不同的心梗塞尺寸的比较重要的。第二，在布安溶液中的部分的过夜固定是至关重要的，以获得明亮的?...

心肌梗死（MI）是全球死亡和残疾的主要原因。冠状动脉心脏疾病是主要原因; MI缺血连续冠脉事件，如阻塞造成的。当未在第一6小时内进行再灌注，局部缺血诱导的不可逆的心肌坏死。在患者中，心肌梗死的表征依赖于不同的诊断工具，包括临床体征，心电图，生物标志物，超声心动图，MRI影像的血浆水平的评估，以及组织学分析1。急性和慢性心肌梗塞是根据相对于冠状动脉闭塞时的心肌坏死的定时列为损伤的两个不同阶段。急性期，在第7天发生，与心肌细胞的损失，广泛炎症，和成纤维细胞的招募相关联。亚急性期，其特征在于所述心脏组织和瘢痕形成的愈合，发生1和4之间 - 6周。梗死，心室壁变薄，心室扩张的扩张表征慢性期。左心室重构粗放逐步导致严重的心脏衰竭2。 MI永久左前降支（LAD）结扎引起慢性代表心肌梗死的标准啮齿动物模型。冠状动脉结扎模仿冠状动脉闭塞。梗塞的大小取决于该结扎的部位上。是用经典的生物标志物血浆水平，如肌钙蛋白执行在啮齿动物模型心肌缺血损伤的表征我和T 3，超声心动图，MRI和组织学4,5。生物标记水平与心肌死亡的程度相关。超声心动图检查评估从区域室壁运动异常导致左心功能受损。此外，非侵入性的成像技术，如MRI或高分辨率超声心动图，允许在壁运动的减少的评估，以减少灌注和存活心肌，和壁变薄的瘢痕区域的体积。 LV尺寸允许梗死面积的准确的评价。最后，可行和死心肌的量化可以用收获内心的组织切片的特殊污渍的进行尸检，并允许梗死面积（IS）的验证。另一个重要的特征是梗塞膨胀指数（EI）6的评价。在EI与内的第3天透梗死并启动有关。在EI的特征在于在壁厚的逐步减少，增加了在LV空腔尺寸，并在左心室的形状随之变化。 为了评估的新的治疗方法的治疗效果 - 尤其是，根据细胞，基质再生策略，以及在啮齿动物中的MI的基因递送精确的评估是极其重要的。当在乳头肌水平而获得的单个横截面测得，在IS大小可能由于存在于梗塞的发展以下LAD结扎的大变异被偏置;心尖梗塞可能会再遮掩。重要的是，更准确的方法来确定的梗死面积已为7-9小鼠或大鼠10所示。然而，IS不足以准确量化左室重构或重塑的治疗引起的减少（或预防措施）。事实上，IS通常表示为评估对心脏的横截面总左心室体积的百分比。虽然这种方法是有效的急性心肌梗死，重塑过程中发生的左心室壁的变薄仍在评估11,12。梗塞大小和结构变化的完整形态量化应量化的几个参数，如心内膜和心外膜的长度和直径，以及梗塞和健康领域。我们描述一个方法论APPRoach准确评估MI和重构的一种慢性大鼠模型。

<table><tbody><tr><td>Acrylic rat heart matrix 2 mm</td><td>72-5015</td><td>Harvard Appartus</td><td></td></tr><tr><td>Inspira advanced volume controlled ventilator</td><td>Harvard Apparatus</td><td>557058</td><td></td></tr><tr><td>Catheter Insyte 14 G</td><td>BD</td><td>381267</td><td></td></tr><tr><td>O.C.T</td><td>BDHA361603E</td><td>VWR</td><td></td></tr><tr><td>TTC</td><td>T8877-10G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Mayer hematoxylin</td><td>MHS32-1L</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Acid Fuchsin&lt;br/&gt; CI 42685</td><td>F8129-50G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Ponceau Xylidin&lt;br/&gt; CI 16150</td><td>P2395-25G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Orange G&lt;br/&gt; CI 16230</td><td>O3756-100G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Light green&lt;br/&gt; CI 42095</td><td>L5382-25G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>KCl</td><td>P9333-500G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Xylol</td><td>10315083</td><td>HoneyWell</td><td></td></tr><tr><td>Ethanol absolute</td><td>10303990</td><td>HoneyWell</td><td></td></tr><tr><td>2-methylbutane</td><td>M32631-1L</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Stereogical microscope</td><td>SM2800</td><td>Nikon</td><td></td></tr><tr><td>Formaldehyde</td><td>99340</td><td>Reactolab</td><td></td></tr><tr><td>Embedding cassette</td><td>K113.1</td><td>Carl Roth</td><td></td></tr><tr><td>Bersoft Image measurement Software</td><td></td><td>Bersoft.com</td><td>Licensed software</td></tr></tbody></table>

histological quantification of chronic myocardial infarct in rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ischemic injury. Following the initial acute phase, chronic remodeling of the left ventricle (LV) modifies the structure and function of the heart. Permanent coronary ligation in small animals has been widely used as a reference model for a chronic model of MI. Thinning of the infarcted wall progressively develops to transmural fibrosis. Histological assessment of infarct size is commonly performed; nevertheless, a standardization of the methods for quantification is missing. Indeed, important methodological aspects, such as the number of sections analyzed and the sampling and quantification methods, are usually not described and therefore preclude comparison across investigations. Too often, quantification is performed on a single section obtained at the level of the papillary muscles. Because novel strategies aimed at reducing infarct expansion and remodeling are under investigation, there is an important need for the standardization of accurate heart sampling protocols. We describe an accurate method to quantify the infarct size using a systematic sampling of harvested rat heart and image analyses of trichromatic stained histological sections obtained from base to apex. We also provide evidence that calculating the expansion index (EI) allowed for infarct size assessment, taking into account changes of the left ventricle throughout the remodeling.

六个星期后LAD结扎，心从Lewis大鼠收获。 2毫米组织切片获得从顶点基地。被执行的TTC染色过程可视化的梗塞面积，这出现在白色，与健康心肌，它出现在红（ 图2）。根据法援署结扎的部位，梗死面积变化。对于大型MI，从顶点观察到基地（ 图2A）透梗死。较小的梗塞呈现白色梗塞组织从顶点到心脏（ 图2B）的中间部分是可见的。对?...

Watch this Scientific Journal Video about Histological Quantification of Chronic Myocardial Infarct in Rats at JoVE.com

Histological Quantification of Chronic Myocardial Infarct in Rats

The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

大鼠慢性心肌梗塞的组织学定量分析

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ...

histological-quantification-of-chronic-myocardial-infarct-in-rats

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

14.4K 次观看.  University of Fribourg. The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections. 

视频: Histological Quantification of Chronic Myocardial Infarct in Rats

Coronary Artery Ligation and Intramyocardial Injection in a Murine Model of Infarction

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo. With the advent of genetic modifications to the whole organism or the myocardium and an array of biological and/or synthetic materials, there is great potential for any combination of these to assuage the extent of acute ischemic injury and impede the onset of heart failure pursuant to myocardial remodeling. 
Here we present the methods and materials used to reliably perform this microsurgery and the modifications involved for temporary (with reperfusion) or permanent coronary artery occlusion studies as well as intramyocardial injections. The effects on the heart that can be seen during the procedure and at the termination of the experiment in addition to histological evaluation will verify efficacy. 
Briefly, surgical preparation involves anesthetizing the mice, removing the fur on the chest, and then disinfecting the surgical area. Intratracheal intubation is achieved by transesophageal illumination using a fiber optic light. The tubing is then connected to a ventilator. An incision made on the chest exposes the pectoral muscles which will be cut to view the ribs. For ischemia/reperfusion studies, a 1 cm piece of PE tubing placed over the heart is used to tie the ligature to so that occlusion/reperfusion can be customized. For intramyocardial injections, a Hamilton syringe with sterile 30gauge beveled needle is used. When the myocardial manipulations are complete, the rib cage, the pectoral muscles, and the skin are closed sequentially. Line block analgesia is effected by 0.25% marcaine in sterile saline which is applied to muscle layer prior to closure of the skin. The mice are given a subcutaneous injection of saline and placed in a warming chamber until they are sternally recumbent. They are then returned to the vivarium and housed under standard conditions until the time of tissue collection. At the time of sacrifice, the mice are anesthetized, the heart is arrested in diastole with KCl or BDM, rinsed with saline, and immersed in fixative. Subsequently, routine procedures for processing, embedding, sectioning, and histological staining are performed. 
Nonsurgical intubation of a mouse and the microsurgical manipulations described make this a technically challenging model to learn and achieve reproducibility. These procedures, combined with the difficulty in performing consistent manipulations of the ligature for timed occlusion(s) and reperfusion or intramyocardial injections, can also affect the survival rate so optimization and consistency are critical.

Numerous genetic manipulations and/or intramyocardial injections of genes, proteins, cells, and/or biomaterials are superimposed upon the dimension of time in studies of acute ischemia/ reperfusion injury and chronic remodeling in mice. This video illustrates the microsurgical procedures for ischemia/reperfusion, permanent coronary artery ligation, and intramyocardial injection studies.

结扎冠状动脉内注射在小鼠模型梗死

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo.  With the advent of genetic modifications to ...

科研

医学

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

This method outlines the use of Quantum Micro-Computed Tomography (MicroCT) to assess cardiac morphology, function, perfusion, metabolism and viability with iodinated contrast agent in mice with experimentally-induced myocardial ischemia. The technique can be applied for non-destructive high-throughput longitudinal in vivo imaging of various animal models of human heart disease.

在心肌结构，功能的体内定量评估，灌注与活力使用心脏微型计算机断层扫描

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that ...

生物工程

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

在诱导小鼠心肌梗死的微创手术过程

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

急性心肌梗死的猪模型主要成果评估

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine models of MI with permanent ligation of left-anterior descending (LAD) coronary artery closely mimics MI in humans. Murine models benefit from the extensive genetic engineering available nowadays. Here we propose a reproducible murine surgical model of myocardial infarction by permanent LAD coronary ligation. Our technique comprises anesthesia with ketamine/xylazine that can be rapidly reversed by administration of an antagonist, intubation without tracheotomy for mechanical-assisted ventilation, ventilation with application of extrinsic positive end-expiratory pressure (PEEP) to avoid alveolar collapse, a thoracotomy method limiting to the minimum surgical lesions made to skeletal muscles, and lung inflation without thoracentesis. This method is sparsely invasive, reproducible and reduces post-surgery mortality and complications.

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological processes.

使用左前部降冠动脉的永久结扎的月心肌梗死模型

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine ...

A New Model of Heart Failure Post-Myocardial Infarction in the Rat

Ligation of the left anterior descending (LAD) coronary artery has been widely used to establish the rat model of heart failure (HF) post myocardial infarction (MI). However, the disadvantages of this model include high mortality rate after ligation and larger variations both in the infarct size and the degree of impaired cardiac function. In addition, a ventilator or exteriorization of the heart is indispensable for the previous models, which complicates the procedure during the ligation. In this study, we developed a reliable and reproducible model without the ventilator or exteriorization of the heart by ligating the LAD coronary artery. Four weeks after the procedure, we found that the serum concentrations of CK-MB, NT-proBNP, and Renin, which were used to assist diagnoses of MI and HF, were significantly higher in the MI group compared to the sham group. In contrast, the value of left ventricle ejection fraction (LVEF) in the MI group was obviously less than in the sham group. Furthermore, the infarct size and cardiac fibrosis area were individually confirmed and quantitatively analyzed by TTC staining and Masson's trichrome staining. Smaller variations were found in either infarct size or fibrosis area in the MI group, which helped to develop a reliable and reproducible model of HF post-MI. This new model of HF post-MI in the rat is vital for studying the potential mechanisms of MI and HF. This new method can be used to develop the new drug for treatment of MI and HF in rats by using pharmacological strategies.

We successfully developed a reliable and reproducible model of heart failure post-myocardial infarction in the rat without ventilation or exteriorization of the heart. This simplifies the procedure and benefits the further studies about the potential mechanisms behind the heart failure.

Ligation of the left anterior descending (LAD) coronary artery has been widely used to establish the rat model of heart failure (HF) post myocardial ...

An Intact Pericardium Ischemic Rodent Model

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to induce myocardial injury). The majority of pre-clinical myocardial infarction models require the disruption of pericardial integrity with loss of the homeostatic cellular milieu. However, recently a methodology has been developed by us to induce myocardial infarction, which minimizes pericardial damage and retains the heart&#39;s resident immune cell population. An improved cardiac functional recovery in mice with an intact pericardial space following coronary ligation has been observed. This method provides an opportunity to study inflammatory responses in the pericardial space following myocardial infarction. Further development of the labeling techniques can be combined with this model to understand the fate and function of pericardial immune cells in regulating the inflammatory mechanisms that drive remodeling in the heart, including fibrosis.

This protocol outlines the steps for inducing myocardial infarction in mice while preserving the pericardium and its contents.

完整的心包缺血性啮齿动物模型

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to ...

Generation and Characterization of Right Ventricular Myocardial Infarction Induced by Permanent Ligation of the Right Coronary Artery in Mice

Right ventricular infarction (RVI) is a common presentation in clinical practice. Severe RVI can lead to fatal hemodynamic dysfunction and arrhythmia. In contrast to the extensively used mouse myocardial infarction (MI) model generated by left coronary artery ligation, the RVI mouse model is rarely employed due to the difficulty associated with model generation. Research on the mechanisms and treatment of RVI-induced RV remodeling and dysfunction requires animal models to mimic the pathophysiology of RVI in patients. This study introduces a feasible procedure for RVI model generation in C57BL/6J mice. Further, this model was characterized based on the following: infarct size evaluation at 24 h after MI, assessment of cardiac remodeling and function with echocardiography, RV hemodynamics assessment, and histology of the infarct zone at 4 weeks after RVI. In addition, a coronary vasculature cast was performed to observe the coronary arterial arrangement in RV. This mouse model of RVI would facilitate the research on mechanisms of right heart failure and seek new therapeutic targets of RV remodeling.

There are several differences between the right and left ventricles. However, the pathophysiology of right ventricular infarction (RVI) has not been clarified. In the present protocol, a reproducible method for RVI mouse model generation is introduced, which may provide a means to explain the mechanism of RVI.

小鼠右冠状动脉永久结扎诱导的右心室性心肌梗死的生成与表征

Right ventricular infarction (RVI) is a common presentation in clinical practice. Severe RVI can lead to fatal hemodynamic dysfunction and arrhythmia. In ...

Ultrasound-Guided Induced Pluripotent Stem Cell-Derived Cardiomyocyte Implantation in Myocardial Infarcted Mice

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a promising cell source for cardiac repair after ischemic damage. However, a low grafted rate is a significant obstacle for effective cardiac tissue regeneration after transplantation. This protocol shows that multiple hiPSC-CM ultrasound-guided percutaneous injections into an MI area effectively increase cell transplantation rates. The study also describes the entire hiPSC-CM culture process, pretreatment, and ultrasound-guided percutaneous delivery methods. In addition, the use of human mitochondrial DNA help detect the absence of hiPSC-CMs in other mouse organs. Lastly, this paper describes the changes in cardiac function, angiogenesis, cell size, and apoptosis at the infarcted border zone in mice 4 weeks after cell delivery. It can be concluded that echocardiography-guided percutaneous injection of the left ventricular myocardium is a feasible, relatively invasive, satisfactory, repeatable, and effective cellular therapy.

Ultrasound-guided cell delivery around the site of myocardial infarction in mice is a safe, effective, and convenient way of cell transplantation.

超声引导诱导多能干细胞来源心肌细胞植入心肌梗死小鼠

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem ...

An Experimental Model of Myocardial Infarction for Studying Cardiac Repair and Remodeling in Knockout Mice

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. This paper describes a protocol for studying the role of galectin 3 (Gal-3) in the temporal evolution of cardiac healing and remodeling in an experimental animal model of MI. 
The procedures described include an experimental model of MI with a permanent coronary ligature in male C57BL/6J (control) and Gal-3 knockout (KO) mice, an echocardiography procedure to study cardiac remodeling and systolic function in vivo, a histological evaluation of interstitial myocardial fibrosis with picrosirius red-stained and rhodamine-conjugated lectin-stained sections for studying myocyte hypertrophy by the cross-sectional area (MCSA), and the quantification of infarct size and cardiac remodeling (scar thinning, septum thickness, and expansion index) by planimetry in slices stained with Masson's trichrome and triphenyl tetrazolium chloride. Gal-3 KO mice with MI showed disrupted cardiac remodeling and an increase in the scar thinning ratio and the expansion index. At the onset of MI, myocardial function and cardiac remodeling were also severely affected. At 4 weeks post MI, the natural evolution of fibrosis in infarcted Gal-3 KO mice was also affected. 
In summary, the experimental model of MI is a suitable model for studying the temporal evolution of cardiac repair and remodeling in mice with the genetic deletion of Gal-3 and other animal models. The lack of Gal-3 affects the dynamics of cardiac repair and disrupts the evolution of cardiac remodeling and function after MI.

Here, we describe an experimental model of myocardial infarction, an echocardiography procedure to study cardiac remodeling and function, and procedures for quantifying fibrosis and hypertrophy in picrosirius red-stained and rhodamine-stained sections, as well as the infarct size and expansion index in slices stained with Masson's trichrome.

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. ...