This work was supported by Merit Review awards (BX002332 and BX000640) from the Biomedical Laboratory Research and Development Service of the Veterans Affairs Office of Research and Development, National Institutes of Health (R15HL129140), and funds from Institutional Research and Improvement account. The project is supported in part by the National Institutes of Health grant C06RR0306551.

在动物身上进行的所有的外科手术应根据指南的护理实验动物13或其他适当的伦理准则的使用和进行。协议应在继续之前，与相应的机构的动物福利委员会的批准。 1.准备心电图注:在开始之前，不要包括手套，眼镜和一个干净的实验室外套或一次性的礼服个人防护装备。 <ol><li>使用非酒精和非漂白基于除污溶液清洁所述ECG垫。轻轻使用微妙的任务抹布擦拭掉多余的溶液，以确保电极焊盘不被损坏。 </li><li>如果ECG垫具有加热功能，使用它。麻醉小鼠倾向于迅速失温。加热垫40-42℃，在整个手术14保持正常体温的体温为37℃。显示器机身脾气ATURE使用直肠体温计。必要时调整垫温度保持体温〜37℃。 </li><li>由于大部分开胸用鼠标趴在它的后面（平卧）执行，确保切换翻转的"仰卧"设置。许多心电图垫具有的功能俯卧和仰卧位置之间切换。若未选择正确的方向可能会导致心电图事件的不实陈述。 </li><li>麻醉，用5％异氟醚吸入和1升/分钟氧气鼠标。一旦小鼠被麻醉，转印鼠标心电图垫配备有麻醉鼻锥和减少异氟烷以2％和1升/分钟的氧气。确认通过确保鼠标在鼠标的脚用钳子捏不恰当的反应麻醉。 </li><li>敷眼润滑药膏薄薄一层在老鼠的眼睛，以防止干燥和角膜损害，同时麻醉。 </li><li>清洁鼠标的爪子用湿擦拭以去除所有可见的床上用品可能卡住的爪子或可以与电脉冲从爪子到ECG垫的传输造成干扰。干爪子带有擦拭。 </li><li>应用高导电电解质凝胶的少量（比美元硬币稍小），以每个在ECG垫的四个金属电极。 注意:一定要只适用凝胶少量的太多凝胶使得它难以自抑的爪子用胶布垫。此外，爪子很可能在手术过程中滑出克制的，如果他们申请磁带之前湿润。 </li><li>在仰卧位鼠标，可以使用明确医用胶带每个爪子抑制到其相应的电极（ 图1）。首先按每个爪子到一块胶布，然后坚持的磁带心电图垫。确保每个约束爪是与电解质凝胶和电极接触。 </li></ol> 2.获取心电图<ol><li>根据用于心电采集，conf下的设备上igure机器，使得ECG波形可以实时可视化。用于使用超声机器上的生理监测设定心电图记录，一个活B模式图像将具有沿屏幕的底部运行ECG波形。 注意:请参阅个人计算机用户指南，确定如何最好地配置设备。 </li><li>通过按压超声机器上的B模式键或其他ECG记录设备的等效使心电波形的实时可视化。 <ol><li>调整分辨率，占幅度的差异。如果Q波的R波或槽（谷）的峰值都出了视觉帧的，调整分辨率，直到波形的整个高度可被观察到。 注:这可以在生理设置选项卡下的超声心动图检查机器上完成。点击增加或减少箭头，直到整个波形是可见的。 </li></ol></li><li>任何时候，一个图像是要OBTained，清除工具的心电图垫。心电图记录用镊子或手指触摸时鼠标会扰乱波形。确保鼠标仍然是和原始心电图上垫记录任何心电图之前。 </li><li>鼠标进行任何手术切口之前，请使用本机的"记录"或"存储"功能。此图片稍后将作为基准进行比较。 </li></ol> 3，手术过程及心电记录<ol><li>开始之前注射麻醉小鼠具有镇痛（丁丙诺啡，1.5微克，腹腔内）。缺血/再灌注外科手术的细节也可以在其他地方5找到。 </li><li>周围的手术部位去除毛发化学或机械和消毒用优碘溶液的区域。使用手术刀，使平行于食道和气管纵切口。轻轻移动到切口的每一侧的淋巴结，直到薄组织覆盖气管是裸露。使用镊子，轻轻直到气管的白软骨环是可见组织中分离出来。 注:我们通常使用奈尔脱毛露。洗剂被施加于手术部位为约1分钟。奈尔然后彻底用生理盐水或水洗掉。此方法是优选的在我们的实验室，因为高分辨率超声心动图（其可检测毛囊）的手术前和手术后进行。但是，需注意避开敏感区域，如生殖器，然后彻底冲洗掉奈尔以避免潜在的皮肤灼伤。 </li><li>迅速从鼻锥去除老鼠的鼻子和插入通风管插入鼠标的嘴，朝喉咙。当通风管的尖端是通过暴露的颈部区域中可见，对准管与气管的开始。轻轻扭动管一边施加上行压力，直到管滑入气管，可从视觉上确认吨至另一侧hrough半透明气管。 </li><li>确保鼠标在插管过程中保持麻醉。从插管暂停和鼠标返回到鼻锥是否开始蠢蠢欲动。 </li><li>使用字符串的循环，通过循环勾鼠标的两颗门牙，并用胶带将字符串结尾的心电图垫稳鼠标的头部，并确保通风管手术过程中不会移动。快速连接的通风管连接到动物呼吸机，并根据鼠标的重量调整通风设置。到位磁带通风管道。 </li><li>覆盖了鼠标在温生理盐水浸湿纱布暴露气管，以保持组织的干燥。 </li><li>使用沿着胸骨的左侧手术刀的垂直切口。 </li><li>使用镊子，轻轻筋膜层从肌肉层分离。小心切割下面的肌肉层不削减可见血管。 </li><li>使用镊子，抢第三肋并拉动轻轻向上。保持在肋握一只手，用手术剪刀小心切开第三和第四肋骨之间的肋间肌组织。确保肺部没有损坏。 注意:肺将缩回到胸腔几乎立即胸腔由手术切口凿孔之后由于压力梯度的丧失。等到肺部在继续之前收回。 </li><li>使用镊子抓，轻轻环绕心脏心包的薄层分开。 </li><li>插入牵开器或手动使用镊子作为肋拉钩到肋骨移动到一个位置，其中心脏是肋之间可见。 注意:这是使得其结扎的放置期间重叠右下爪移动鼠标的左下爪子常见的做法。这有助于在心脏定位，以使左心耳，或耳廓，是结扎的放置过程中很容易地看到。请注意，有效的心电图W¯¯而左下爪子熄灭电极aveforms不能获得。出于这个原因，建议该缝合结扎穿过心肌组织，但结紧固前通过后爪返回其电极。 </li><li>找到LAD视觉，左耳廓下方。迅速插入7-0丝锥形缝合针到心肌足够深入的LAD下通过，但没有那么深穿透LV腔。通过直到有4厘米左右留在缝合结扎的自由（非针）结束缝合丝拉出缝合结扎。 </li><li>开始绑一个简单的缝合打结。一旦缝合丝的自由端已通过环拉以形成结，暂停。 </li><li>同时持有钳缝合丝的自由和针端插入PE-10管的约1cm部分形成结下方，上盖的心外膜表面。 </li><li>如果鼠标的左爪子被超过，返回爪子其亲每个电极。以便在PE-10管缝合到心脏紧结。释放与鼠标所有物理接触，以允许要被记录的ECG。 </li><li>通过对〜10秒让心电波形循环。目视检查，心电波形和记录波形为"闭塞的时代"。如果T波不振幅1分钟内增加，重新评估结扎的位置。 <ol><li>如果T波振幅也不会增加，无论是从研究丢弃动物或试图纠正结扎位置。 </li></ol></li><li>目视检查心肌的颜色来确认LV缺血变白。 </li><li>如果心电图改变和心肌颜色变化表明缺血，成双结对周围的PE-10管缝合。 </li><li>盖打开胸腔用温生理盐水纱布。 </li><li>记录心电图每5-10分钟的局部缺血期的持续时间。 </li></ol> 4.确认再灌注的使用心电图<ol><li>取出盐水纱布海湾环胸腔和可视化的心脏。 </li><li>用刀片切割缝合丝的PE-10管上面。一旦结扎切断，去除PE-10管的部分，轻轻取出从心肌缝合结扎。 </li><li>释放与鼠标所有物理接触，并允许所述ECG波形〜10秒循环。作为记录波形"再灌注的时间。"继续达到所需的实验时间点直到记录ECG波形每次5-10分钟。 </li><li>根据需要调整变化幅度分辨率。如果T波时不除去在PE-10管材和结扎的改变，再灌注未确认。 <ol><li>如果T波时不去除管子改变，无论是从研究丢弃动物或试图纠正结扎位置。 </li></ol></li><li>目视检查心肌组织回红颜色还确认再灌注。 </li><li>关闭胸腔用5-0缝合肋间同时施加温和的压力，鼠标的胸部驱逐手术过程中已经进入过剩空气丝线缝合。然后缝合肌肉层，最后皮肤。注:施加压力至胸腔可能不足以疏散空气的胸腔中所有小鼠。因此，应采用疏散的注射器和针头的方法，以确保所有的空气已经被排出。 </li><li>从电极旋转吸入麻醉关闭和删除鼠标的爪子之前记录的最后一个心电图。增加氧气到2升/分钟，直到鼠标苏醒保持通风。 </li><li>允许小鼠恢复在恒温控制的环境中， 例如，加热垫或暖培养箱，以避免梗塞变性。根据需要由鼠标鬼脸刻度所指示的治疗小鼠与丁丙诺啡24小时的手术后，然后。 注意:程序再灌注也详细Xu 等人讨论了5。 </li></ol>

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The authors have nothing to disclose.

使用心电图改变为确认心肌缺血再灌注补充的方法，确保咬合结扎的准确位置。结扎的位置精度是减少动物之间的数据变化的关键。在小鼠心脏的LAD是一个困难的动脉可视化。因此，补充的视觉与苍白心电图改变将有助于确保结扎并导致组织损伤的正确位置。 自所述ECG垫提供心脏的非侵入性的观点，可以在研究过程中获得的多个心电图。这可以帮助提供更好的理解期间和手?...

心脏疾病仍然死亡全世界1,2的主要原因。不仅是左心室（LV）的最肌肉室，负责从心脏泵血对整个主体3，它是一个常见的心脏损伤部位心肌梗死后4。左心室组织死亡往往会导致心脏收缩功能衰竭。心脏疾病的动物模型是当务之急生物医学心血管研究的进步。小鼠C57BL / 6株已用于动物模型的流行选择由于它们的快速繁殖的时间，成本低和易于在遗传改变。心脏疾病的研究大多数小鼠模型手术涉及到左冠状动脉的LAD支闭塞。在LAD有时称为左钝缘5,6。法援署提供血液到左室前壁和安特罗侧壁。结扎研究的目的是诱导前梗塞，有时延长INT澳劣质和侧壁区7。 经常使用心肌梗塞研究两个模型包括慢性阻塞心肌梗塞和心肌缺血/再灌注损伤。慢性阻塞是通过手术缝合周围，阻止永久通过LAD血流创建。缺血/再灌注损伤被创建以相同的方式多只用一个短暂的，通常是30-60分钟，局部缺血期。实现短暂缺血，周围LAD咬合缝合关系和一个小的PE-10管，其被平行放置在LAD心脏的心外膜表面上，随后再灌注期，其中管子和封闭缝合被去除，血液是使其再次通过动脉并进入心肌流动。缺血/再灌注手术已被认为是临床相关的因再灌注损伤人体平行梗塞治疗，其中包括舞会的性质PT冠状动脉成形术和动脉支架置入，或冠状动脉旁路。典型地，这些手术期间，在小鼠心脏左心室的缺血是由心肌壁的可见苍白证实。但是，通过简单地不断监测条件下的心电图（ECG）垫进行手术，可在ECG波形观察到明显的变化，从而证实小鼠心肌缺血再灌注损伤。 虽然小鼠心脏在许多方面，包括它的四腔结构类似于人类的心脏，心中也有差异。一个明显的区别是成年小鼠的平均静息心脏速率为600 -每分钟（BPM）700次，而成人人类是60-100〜8,9 BPM。此外，在小鼠复极化波，J和T，常合并与除极QRS波群作出明确的ST段难以辨别10。要复杂electrocardiographicall的过程ý确认心肌缺血，它是T波和用作缺血和心肌梗死损伤在人体中的诊断标志物的ST段的抬高，临床上称为STëlevation 米 yocardial 我 nfarction或STEMI。一个人和鼠的波形之间的主要区别是，S波之后紧接着是J-波直接传送到负T波。期间小鼠急性心肌缺血S波减小的幅度，并随后直接由异常的J-波和倒T波11。 T波似乎没有在小鼠中11来表示复极化的显著一部分。尽管命名和鼠标与人类不同，小鼠心肌缺血再灌注心电图确认是仍然可行和相对简单的。为了简化波形解释的缘故，SJT之间的段被称为ST-segmeNT于此。 发表于2013 STEMI指南推荐小于90分钟12患者门到气球时间。这意味着从患者的冠状动脉闭塞的识别的时间帧，直至动脉重新打开应小于90分钟。跳动的心脏不断工作，因此，具有较高的氧化代谢和氧耗3的较高水平。为了提供这一点，毛细血管的网络是可用于每个肌细胞3。只需要一个心脏跳动数耗尽它的氧气和营养供应。在90分钟的窗口，在一个人的缺血性心脏地区将被封锁接收5400名点附近摇摆心脏跳动的富含氧气的血液的价值。在同样的90分钟的窗口，鼠标将有54000 63000心脏跳动。对鼠缺血/再灌注损伤的实验时间点通常是30分钟和60分钟之间。 发展的重要性ING证实了小鼠模型心肌缺血再灌注的补充方法对心肌缺血/再灌注损伤的研究数据的一致性和可重复性产生深远的影响。目视观察心脏的组织颜色改变目前的做法是不够的作为一个独立的诊断。此外，除去管和缝合之后再灌注不能保证。虽然动脉不再打结，动脉可具有在手术期间持续伤害，并可能成为不可能reperfuse。这将是有益的的心电图变化的记录，以确认再灌注而不是依赖于心肌苍白和发红（红色）的意见。心不显示缺血/再灌注损伤的标记就可以迅速被标记，并就如何继续处理的决定可以由侦查进行。 最后，建立心电图的记录从基线整个日变化Ë缺血再灌注时间允许调查人员继续初次手术后监测心脏。目前调查的手术完成后尽快忘记的心脏。心电图是深入了解手术后在心肌小时发生至数天变化的简单方法。心电图记录的时间点，手术后可以揭示表明持续或恶化的组织死亡后发Q波。然而，为了有效地测厚仪新的或恶化的心电图标记，一个基线ECG必须可用于比较。 该协议将展示如何准备，获取和解读心电图，确认使用8小鼠心脏缺血再灌注 - 19周龄雄性C57BL / 6小鼠。

<table><tbody><tr><td>Vevo 1100</td><td>Fujifilm&lt;br/&gt; Visual Sonics</td><td></td><td>Echocardiography Machine</td></tr><tr><td>Mouse Handling Plate</td><td>Fujifilm&lt;br/&gt; Visual Sonics</td><td></td><td>Heated ECG plate</td></tr><tr><td>Signa-Gel&amp;nbsp;</td><td></td><td></td><td>Highly Conductive Multi-</td></tr><tr><td>Electrode Gel</td><td>Parker</td><td>15-25</td><td>Purpose Electrolyte</td></tr><tr><td>Transpore Medical Tape</td><td>3M</td><td>1527-0</td><td></td></tr><tr><td>PI-Spray II</td><td>Pharmaceutical Innovations</td><td>NDC 36-2013-25</td><td>Cleaning agent for ECG plate</td></tr><tr><td>C57Bl6 Mice</td><td>The Jackson Laboratory</td><td>000664</td><td>Male, 8 - 12 wk</td></tr><tr><td>IsoThesia-Isoflurane</td><td>Henry Schein</td><td>NDC 1169-0500-1</td><td></td></tr><tr><td>Excel</td><td>Microsoft</td><td></td><td></td></tr><tr><td>Systane Nighttime Lubricant Eye Ointment</td><td>Alcon</td><td>65050935</td><td></td></tr><tr><td>7-0 Perma-Hand Silk Sutures</td><td>Ethicon</td><td>640.O32</td><td></td></tr><tr><td>5-0 Perma-Hand Silk Sutures</td><td>Ethicon</td><td>K809.O32</td><td></td></tr><tr><td>Surgical Scissors</td><td>ROBOZ</td><td>RS-5881</td><td></td></tr><tr><td>Forceps</td><td>Fine Science Tools</td><td>11052-10</td><td></td></tr><tr><td>Gauze</td><td>Bio Nuclear Diagnostics Inc</td><td>DIS-022B</td><td></td></tr><tr><td>Needle Holder</td><td>Fine Science Tools</td><td>12565-14</td><td></td></tr><tr><td>Buprenex CIII&amp;nbsp;</td><td>Patterson Veterinary</td><td>0-891-9756</td><td>Buprenorphine Hydrochloride Analgesic&amp;nbsp;</td></tr><tr><td>Betadine</td><td>Purdue Products</td><td>67618-150-08</td><td></td></tr><tr><td>Nair</td><td>Church and Dwight Co.</td><td>NRSL-22339-05</td><td></td></tr></tbody></table>

confirmation of myocardial ischemia and reperfusion injury in mice using surface pad electrocardiography

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality worldwide. In humans, a pathologic occlusion forms in a coronary artery and reperfusion of that occluded artery is considered essential to maintain viability of the myocardium at risk. Although essential for myocardial recovery, reperfusion of the ischemic myocardium creates its own tissue injury. The physiologic response and healing of an ischemia/reperfusion injury is different from a chronic occlusion injury. Myocardial ischemia/reperfusion injury is gaining recognition as a clinically relevant model for myocardial infarction studies. For this reason, parallel animal models of ischemia/reperfusion are vital in advancing the knowledge base regarding myocardial injury. Typically, ischemia of the mouse heart after left anterior descending (LAD) coronary artery occlusion is confirmed by visible pallor of the myocardium below the occlusion (ligature). However, this offers only a subjective way of confirming correct or consistent ligature placement, as there are multiple major arteries that could cause pallor in different myocardial regions. A method of recording electrocardiographic changes to assess correct ligature placement and resultant ischemia as well as reperfusion, to supplement observed myocardial pallor, would help yield consistent infarct sizes in mouse models. In turn, this would help decrease the number of mice used. Additionally, electrocardiographic changes can continue to be recorded non-invasively in a time-dependent fashion after the surgery. This article will demonstrate a method of electrocardiographically confirming myocardial ischemia and reperfusion in real time.

正常鼠心电图与用于电事件P，Q，R，S，J和T P字母标记显示在图2中是初始心房去极化。 QRS是去极化在心室的浪潮。 J是早期复极T表示异构的复极又称恢复11。应该指出的是，许多实验室不使用的J形波命名法，而是指SJT段作为ST段10,15-17。在这里，结果和分析具有代表性和基于关闭40只小鼠的实验观察。大多数小鼠在手术的过程中表现出类似的波...

Watch this Scientific Journal Video about Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography at JoVE.com

Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

During murine myocardial ischemia/reperfusion surgery, correct placement of the occluding ligature is typically confirmed by visible observation of myocardial pallor. Herein, a method of electrocardiographically confirming ischemia and reperfusion, to supplement observed myocardial pallor, is demonstrated in male C57Bl/6 mice.

小鼠使用表面垫心电图心肌缺血再灌注损伤的确认

Many animal models have been established for the study of myocardial remodeling and heart failure due to its status as the number one cause of mortality ...

confirmation-myocardial-ischemia-reperfusion-injury-mice-using

Research

JoVE Journal

Medicine

13.2K 次观看.  East Tennessee State University. During murine myocardial ischemia/reperfusion surgery, correct placement of the occluding ligature is typically confirmed by visible observation of myocardial pallor. Herein, a method of electrocardiographically confirming ischemia and reperfusion, to supplement observed myocardial pallor, is demonstrated in male C57Bl/6 mice.

视频: Confirmation of Myocardial Ischemia and Reperfusion Injury in Mice Using Surface Pad Electrocardiography

Programmed Electrical Stimulation in Mice

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ventricular arrhythmias, and sudden cardiac death.1 Intracardiac pacing studies can be performed in mice using a 1.1F octapolar catheter inserted into the jugular vein, and advanced into the right atrium and ventricle. Here, we illustrate the steps involved in performing programmed electrical stimulation in mice. Surface ECG and intracardiac electrograms are recorded simultaneously in the atria, atrioventricular junction, and ventricular myocardium, whereas intracardiac pacing of the atrium is performed using an external stimulator. Thus, programmed electrical stimulation in mice provides unique opportunities to explore molecular mechanisms underlying conduction defects and cardiac arrhythmias.

Programmed electrical stimulation provides the ability to determine conduction properties of the heart, and the possibility to induce and terminate cardiac arrhythmias using various pacing protocols. Using a transvenous catheter, intracardiac electrogram recordings can be obtained in mice following programmed electrical stimulation protocols to identify arrhythmogenic substrates.

程控电刺激小鼠

Genetically-modified mice have emerged as a preferable animal model to study the molecular mechanisms underlying conduction abnormalities, atrial and ...

科研

医学

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized.  The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed. 

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine heart.

高频超声心动图：非侵入性的反复测量小鼠心脏缺血再灌注心肌劳损，收缩力，二尖瓣关闭不全的第一个证据

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

Modified Technique for Coronary Artery Ligation in Mice

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI we need better knowledge about pathophysiology of myocardial ischemia. This knowledge may be valuable to define new therapeutic targets for innovative cardiovascular therapies4. Experimental MI model in mice is an increasingly popular small-animal model in preclinical research in which MI is induced by means of permanent or temporary ligation of left coronary artery (LCA)5. In this video, we describe the step-by-step method of how to induce experimental MI in mice.
The animal is first anesthetized with 2% isoflurane. The unconscious mouse is then intubated and connected to a ventilator for artificial ventilation. The left chest is shaved and 1.5 cm incision along mid-axillary line is made in the skin. The left pectoralis major muscle is bluntly dissociated until the ribs are exposed. The muscle layers are pulled aside and fixed with an eyelid-retractor. After these preparations, left thoracotomy is performed between the third and fourth ribs in order to visualize the anterior surface of the heart and left lung. The proximal segment of LCA artery is then ligated with a 7-0 ethilon suture which typically induces an infarct size ~40% of left ventricle. At the end, the chest is closed and the animals receive postoperative analgesia (Temgesic, 0.3 mg/50 ml, ip). The animals are kept in a warm cage until spontaneous recovery.

The surgical procedure used to induce experimental myocardial infarction in mice begins with left thoracotomy between the third and the fourth ribs in order to visualize the anterior surface of the heart and left lung. The left coronary artery is ligated, the chest is closed and the mouse is allowed to recover spontaneously.

改性技术在小鼠冠状动脉结扎

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI ...

A Murine Closed-chest Model of Myocardial Ischemia and Reperfusion

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ischemia and reperfusion. Immune response includes cytokine expression and release or secretion of endogenous ligands of innate immune receptors. Activation of innate immunity can potentially modulate infarct size. We have modified an existing murine closed-chest model using hanging weights which could be useful for studying myocardial pre- and postconditioning and the role of innate immunity in myocardial ischemia and reperfusion. This model allows animals to recover from surgical trauma before onset of myocardial ischemia.
Volatile anesthetics have been intensely studied and their preconditioning effect for the ischemic heart is well known. However, this protective effect precludes its use in open chest models of coronary artery ligation. Thus, another advantage could be the use of the well controllable volatile anesthetics for instrumentation in a chronic closed-chest model, since their preconditioning effect lasts up to 72 hours. Chronic heart diseases with intermittent ischemia and multiple hit models are other possible applications of this model.
For the chronic closed-chest model, intubated and ventilated mice undergo a lateral blunt thoracotomy via the 4th intercostal space. Following identification of the left anterior descending a ligature is passed underneath the vessel and both suture ends are threaded through an occluder. Then, both suture ends are passed through the chest wall, knotted to form a loop and left in the subcutaneous tissue. After chest closure and recovery for 5 days, mice are anesthetized again, chest skin is reopened and hanging weights are hooked up to the loop under ECG control.
At the end of the ischemia/reperfusion protocol, hearts can be stained with TTC for infarct size assessment or undergo perfusion fixation to allow morphometric studies in addition to histology and immunohistochemistry.

Surgical trauma induces an inflammatory response. Cytokines and endogenous ligands are known to modulate myocardial infarct size following ischemia and reperfusion. We present a modified closed-chest model of murine ischemia and reperfusion using hanging weights to minimize effects of thoracotomy.

闭胸鼠心肌缺血再灌注模型

Surgical trauma by thoracotomy in open-chest models of coronary ligation induces an immune response which modifies different mechanisms involved in ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

心肌缺血再灌注损伤的通过左前降支结扎小鼠模型

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

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 Modified Simple Method for Induction of Myocardial Infarction in Mice

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI remodeling and evaluation of novel therapeutics. Different methods (e.g., isoproterenol treatment, cryoinjury, coronary artery ligation, etc.) have been used to induce MI. Compared with isoproterenol treatment and cryoinjury, coronary artery ligation may better reflect the ischemic response and chronic remodeling after MI. However, traditional methods for coronary ligation in mice are technically challenging. The current study describes a simple and efficient process for induction of MI in mice with readily available materials. The mouse chest skin was cut open under stable anesthesia. The heart was immediately externalized through the intercostal space after blunt separation of the pectoralis major and pectoralis minor. The left anterior descending branch (LAD) was ligated with a 6-0 suture 3 mm from its origin. Following LAD ligation, staining with 2,3,5-Triphenyltetrazolium chloride (TTC) indicated successful induction of MI and temporal changes of post-MI scar size. Meanwhile, survival analysis results showed overt mortality within 7 days after MI, mainly due to cardiac rupture. Moreover, post-MI echocardiographic assessment demonstrated successful induction of contractile dysfunction and ventricular remodeling. Once mastered, an MI model can be established in mice within 2-3 min with readily available materials.

Under adequate anesthesia, the mouse heart was externalized through the intercostal space, and myocardial infarction was successfully induced by ligating the left anterior descending artery (LAD) using materials readily available in most laboratories.

一种改良的小鼠心肌梗死诱导简易方法

Myocardial infarction (MI) represents one of the leading causes of death. MI models are widely used for investigating the pathomechanisms of post-MI ...

Induction of Myocardial Infarction and Myocardial Ischemia-Reperfusion Injury in Mice

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of heart reflow and induce secondary myocardial injury. A simple and reproducible model of myocardial infarction and myocardial ischemia-reperfusion injury is a good tool for researchers. Here, a customizable method to create a myocardial infarction (MI) model and MIRI by precision ligation of the left anterior descending coronary artery (LAD) through micromanipulation is described. Accurate and reproducible ligature positioning of the LAD helps obtain consistent results for heart injury. ST-segment changes can help to identify model accuracy. The serum level of cardiac troponin T (cTnT) is used to assess the myocardial injury, cardiac ultrasound is employed to evaluate the myocardial systolic function, and Evans-Blue/triphenyl tetrazolium chloride staining is used to measure infarct size. In general, this protocol reduces procedure duration, ensures controllable infarct size, and improves mouse survival.

Here we describe a simple and reproducible method that can induce myocardial infarction or myocardial ischemia-reperfusion injury in mice by precision ligation of the left anterior descending coronary artery through micromanipulation.

小鼠心肌梗死和心肌缺血再灌注损伤的诱导

Acute myocardial infarction is a common cardiovascular disease with high mortality. Myocardial reperfusion injury can counteract the beneficial effects of ...

Model of Ischemia and Reperfusion Injury in Rabbits

The protocol here provides a simple, highly replicable methodology to induce in situ acute regional myocardial ischemia in the rabbit for non-survival and survival experiments. New Zealand White adult rabbit is sedated with atropine, acepromazine, butorphanol, and isoflurane. The animal is intubated and placed on mechanical ventilation. An intravenous catheter is inserted into the marginal ear vein for the infusion of medications. The animal is pre-medicated with heparin, lidocaine, and lactated Ringer&#39;s solution. A carotid cut-down is performed to obtain arterial line access for blood pressure monitoring. Select physiologic and mechanical parameters are monitored and recorded by continuous real-time analysis.
With the animal sedated and fully anesthetized, either a fourth intercostal space small left thoracotomy (survival) or midline sternotomy (non-survival) is performed. The pericardium is opened, and the left anterior descending (LAD) artery is located.
A polypropylene suture is passed around the second or third diagonal branch of the LAD artery, and the polypropylene filament is threaded through a small vinyl tube, forming a snare. The animal is subjected to 30 min of regional ischemia, achieved by occluding the LAD by tightening the snare. Myocardial ischemia is confirmed visually by regional cyanosis of the epicardium. Following regional ischemia, the ligature is loosened, and the heart is allowed to re-perfuse.
For both survival and non-survival experiments, the myocardial function can be assessed via an echocardiography (ECHO) measurement of the fractional shortening. For non-survival studies, data from sonomicrometry collected using three digital piezoelectric ultrasonic probes implanted within the ischemic area and the left ventricle developed pressure (LVDP) using an apically inserted left ventricle (LV) catheter can be continuously acquired for evaluating the regional and global myocardial function, respectively.
For survival studies, the incision is closed, a left needle thoracentesis is performed for pleural air evacuation, and postoperative pain control is achieved.

The present study demonstrates a highly reproducible animal model of acute regional myocardial ischemia and reperfusion injury in rabbits using a left mini-thoracotomy for survival cases or a midline sternotomy for non-survival cases.

兔子缺血和再灌注损伤模型

The protocol here provides a simple, highly replicable methodology to induce in situ acute regional myocardial ischemia in the rabbit for non-survival and ...

<meta charset="utf8"></head><body>小鼠心肌缺血再灌注损伤的闭胸技术

Remotely Triggered LAD Occlusion Using a Balloon Catheter in Spontaneously Breathing Mice

Acute myocardial infarction (AMI) is a prevalent and high-mortality cardiovascular condition. Despite advancements in revascularization strategies for AMI, it frequently leads to myocardial ischemia-reperfusion injury (IRI), amplifying cardiac damage. Murine models serve as vital tools for investigating both acute injury and chronic myocardial remodeling in vivo. This study presents a unique closed-chest technique for remotely inducing myocardial IRI in mice, enabling the investigation of the very early phase of occlusion and reperfusion using in-vivo imaging such as MRI or PET. The protocol utilizes a remote occlusion method, allowing precise control over ischemia initiation after chest closure. It reduces surgical trauma, enables spontaneous breathing, and enhances experimental consistency. What sets this technique apart is its potential for simultaneous noninvasive imaging, including ultrasound and magnetic resonance imaging (MRI), during occlusion and reperfusion events. It offers a unique opportunity to analyze tissue responses in almost real-time, providing critical insights into processes during ischemia and reperfusion. Extensive systematic testing of this innovative approach was conducted, measuring cardiac necrosis markers for infarction, assessing the area at risk using contrast-enhanced MRI, and staining infarcts at the scar maturation stage. Through these investigations, emphasis was placed on the value of the proposed tool in advancing research approaches to myocardial ischemia-reperfusion injury and accelerating the development of targeted interventions. Preliminary findings demonstrating the feasibility of combining the proposed innovative experimental protocol with noninvasive imaging techniques are presented herein. These initial results highlight the benefit of utilizing the purpose-built animal cradle to remotely induce myocardial ischemia while simultaneously conducting MRI scans.

<meta charset="utf8"></head><body>作者聚焦:一种用于急性心肌损伤实时生物医学成像的新型标准化技术

This article presents a unique closed-chest technique for inducing myocardial ischemia-reperfusion injury (IRI) in mice. The presented method allows mice to breathe spontaneously while remotely inducing myocardial ischemia. This provides access to the animal for studying the dynamic processes of ischemia and reperfusion in situ and in real-time via noninvasive imaging.

在自主呼吸小鼠中使用球囊导管远程触发 LAD 闭塞

Acute myocardial infarction (AMI) is a prevalent and high-mortality cardiovascular condition. Despite advancements in revascularization strategies for ...