我们感谢很多 Frede 和 Susanne 舒尔茨的技术援助。这项研究没有得到任何资助。

这项议定书得到了动物实验 LANUV 雷克林豪森 (#84-02.04.2016 A374) 的伦理委员会的批准。一般情况下, 这一程序是对成年老鼠 > 10 周的年龄。然而, 也有可能对年轻的动物进行这种手术。手术工具必须在使用前消毒, 所有步骤都要在无菌条件下进行。
1. 麻醉和插管的诱导
<ol><li>注射丁丙诺啡0.1 µg/克体重腹腔减轻疼痛。在手术后的三天内, 每8小时重复腹腔注射0.1 毫克/千克丁丙诺啡。</li>
	<li>对于感应, 把鼠标放到一个麻醉感应箱, 它连接到蒸发器设置为3.0 体积% 的异氟醚, 氧气流量为1升/分。</li>
	<li>通过诱导触觉刺激来确保深麻醉。 注: 如果麻醉感应失败或麻醉不够深, 则增加异氟醚的体积% 高达5%。</li>
	<li>捏紧鼠标的尾部, 以确保反射性缺失。在完全没有反射的情况下, 称鼠标为最佳通风机设置 (见 1.12)。</li>
	<li>将鼠标移动到温度控制的操作表中, 在整个过程中保持体温37摄氏度。</li>
	<li>将鼠标的鼻子放在与麻醉感应箱相连的塑料锥中, 以保持麻醉。</li>
	<li>用尼龙缝合固定小鼠上门牙。用胶带把四肢缠在一起。</li>
	<li>用镊子的尖端对后爪施加压力, 以确保再次有足够的麻醉。在缺乏撤退反射继续以以下步骤。 注: 如果麻醉感应失败或麻醉不够深, 等待退出反射, 则增加异氟醚的体积%。</li>
	<li>在角膜上放置无菌眼润滑剂, 以防止麻醉下的干燥。</li>
	<li>润滑直肠探头以避免直肠外伤。插入直肠温度探头, 以确保核心温度为37摄氏度。</li>
	<li>根据制造商的指示, 脱毛喉部和上胸脱毛膏。1分钟后擦掉奶油。如有必要, 请重复此步骤直到成功。 注: 使用棉尖拭子, 以防出血。</li>
	<li>用70% 乙醇清洁脱毛区。然后将聚维酮碘用于局部皮肤消毒3次, 至少3分钟。</li>
	<li>调整呼吸机设置的生理参数。将呼吸速率设置为 150/分钟, 潮汐容积为8-10 µL/克体重 (体重)。</li>
	<li>戴上一双新的无菌手套。将鼠标放在手术显微镜下, 将不育的 fenestrated 悬垂在老鼠身上。</li>
	<li>将下颌下方3毫米的中线切开至 2nd肋。确定颌下腺的中线和结缔组织。然后用角度髋关节钳轻轻地用两个钳在中线上直接划分腺体, 并探讨气管肌。</li>
	<li>用髋关节钳轻轻拉准气管肌肉, 使气管轻柔地准备。</li>
	<li>用镊子拉舌, 使喉部伸直, 以方便插管, 并轻轻插入气管内的插管套管 (外径1.2 毫米)。通过对气管内导管的直接可视化和检查是否正确的胸部运动来确认插管。</li>
	<li>在插管后将异氟醚浓度调整为2% 异氟醚, 流量为1.0 升/分和 100% O2。 注: 如果呼吸运动不停止或老鼠开始移动, 首先增加呼吸率高达 180/分钟。如有必要, 将异氟醚浓度增加到 3.5%, 直到鼠标停止呼吸。评估漏油或不充分填充蒸发器是最常见的问题。</li>
	<li>或者, 按照以下子步骤中的建议执行插管。<ol>
<li>将鼠标放置在一个位于一个角的表上。</li>
		<li>用胶带把老鼠的四肢缠在一起, 把头倾斜。</li>
		<li>将冷光源直接放在喉上方的皮肤上。</li>
		<li>用钳子轻轻地拉舌, 使声带形象化。</li>
		<li>通过声带插入四套管 (24 克) 的塑料管, 并将塑料管连接到通风机设置。</li>
		<li>将呼吸机连接到套管, 通过 synchrone 胸部运动确认插管。 注: 如果呼吸运动不停止或老鼠开始移动, 首先增加呼吸率高达180每分钟。如有必要, 将异氟醚浓度增加到 3.5%, 直到鼠标停止呼吸。评估漏油或不充分的蒸发器作为最可能的问题。</li>
	</ol>
</li>
</ol>2. 术前多普勒测量
<ol><li>用镊子轻轻拉结缔组织, 使颈动脉与气管分开。</li>
	<li>将20兆赫多普勒探针的尖端放置在右侧和左颈动脉的一些无菌超声凝胶上, 其角度小于45°。</li>
	<li>慢慢旋转探头, 将其移动到侧面和内侧以找到多普勒信号, 并倾斜探头以优化信号。</li>
	<li>使用多普勒软件来显示和存储在计算机上的右、左颈总动脉流速。</li>
</ol>3. 开胸术
<ol><li>使用一组不育的手套为每个单独的老鼠, 以防止手术部位感染。</li>
	<li>用剪刀将皮肤切口向下扩展到 2nd肋间空间。</li>
	<li>通过计数肋骨, 然后用髋关节钳直接穿透这个空间, 识别 2nd肋间空间。 注意: 1st肋位于锁骨下, 因此不可见, 因为在第一个可见肋 ( 即2 和肋) 和 3rd肋之间发现2个nd肋间空间。</li>
	<li>在镊子提示的帮助下打开 2nd肋间空间, 然后插入拉钩。</li>
	<li>用附在手术台上的橡皮筋调整拉钩, 以清楚地看到胸腺。</li>
	<li>在出血的情况下使用棉尖, 并按下表面血管2分钟。</li>
</ol>4. 横向主动脉的带状
<ol><li>调整放大倍数为 200%, 以确定中线和结缔组织。然后用角钳轻轻地分割胸腺。清除脂肪组织, 直到主弓可以清楚地看到。</li>
	<li>在头臂大动脉动脉和左颈总动脉之间的横向主动脉下, 准备一条有角栓钳的隧道 (参见图 1)。在精钳的帮助下, 保持6.0 缝合的末端, 并通过主弓下的螺纹。</li>
	<li>从拱的另一侧拿起第二个钳的螺纹。</li>
	<li>切下一个3毫米长的一块27克长度, 使用针作为一个间隔, 用于交结扎的小鼠体重在 19-25 克体重和26克针作为一个间隔为小鼠 > 25 克体重。</li>
	<li>小心地将间隔平行于横向主动脉。</li>
	<li>准备一个松散的双结在间隔, 并确保最佳放置间隔与主动脉平行。然后绑第一个投掷, 并迅速执行第二次相反投掷。立即卸下间隔。</li>
	<li>要执行假鼠控制, 遵循相同的协议, 省略结扎的主动脉。</li>
	<li>用6.0 聚丙烯缝合线关闭 2nd肋间空间。结扎时要特别注意锁骨下血管。</li>
	<li>在连续缝合模式下用6.0 聚丙烯缝合缝合皮肤。</li>
</ol>5. 确认成功结扎横主动脉
<ol><li>将20兆赫多普勒探针放在颈部两侧的45°角上, 如2节。</li>
	<li>记录每一侧的流速。 注意: 成功的 TAC 可以通过多普勒流速来验证, 如图 2所示。在右侧和左颈动脉之间的流速比为 4-10 通常保证足够的 TAC (参见图 2)。</li>
</ol>6. 心脏收获
<ol><li>根据步骤1.2 诱导麻醉。和1.3。</li>
	<li>将鼠标放置在安乐死室中, 调整二氧化碳流速, 以取代体积/分钟的 10-30%。</li>
	<li>把老鼠盯在手术台上。用剪刀打开腹部, 用套管从下腔静脉中收获血液, 进一步分析。</li>
	<li>用强力剪刀切开隔膜和胸骨骨, 取出心脏。</li>
	<li>在重心脏之前, 取出所有的动脉和结缔组织。</li>
	<li>将右心室和隔膜从左心室分开, 并对两个样本进行权衡。</li>
	<li>在液氮中冷冻两个组织样本。</li>
</ol>

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作者没有什么可透露的。

交咨会引起高血压的快速发作不同于因主动脉狭窄或高血压而导致的临床相关肥厚。然而, 使用小动物模型诱发心力衰竭有许多优点, 因此, 许多调查员选择了11。这个闭合的胸部模型改进已经现有的手术技术的模型诱导小鼠横向主动脉收缩4。
最关键的一步是在主动脉弓下的通道。在主动脉周围缝合太紧可能会导致血液流向肾脏等重要器官?...

老鼠模型经常被用来模仿人类疾病1。横向主动脉收缩 (TAC) 用于诱发压力超负荷和左心室肥厚2。用洛克曼et 等方法对小鼠开胸交模型进行了验证。3和手术过程由 DeAlmeida et . 详细描述。4. 与腹主动脉收缩相比, 横向主动脉的带状比较有利, 因为循环的较大部分可以补偿后者程序2的负面影响。
横向主动脉的带状导致上升主动脉和头臂大动脉动脉的动脉压力增加, 但通过远端血管(即左颈总动脉, 左锁骨下侧) 留下足够的器官灌注。动脉和降主动脉)。这导致心脏后负荷增加和心脏壁压力增高。由于纤维加厚5, 壁面应力随后减小。心脏血流动力学的慢性变化导致左心室适应不良和扩张。这样, 交咨会创造一个可重现的心肌肥厚模型, 最终导致心力衰竭。
DeAlmeide et . 所述的 TAC 标准程序。4通过部分上开胸手术, 通过肋骨或胸骨的解剖, 进入纵隔以及胸腔, 接近主动脉弓。这样可以很好地看到主弓及其侧支。不幸的是, 解剖肋骨不能重新附加, 使他们自由浮动, 从而改变呼吸动力学。
因此, 我们通过 2nd肋间空间的侧向手术方法, 建立了一种微创的主动脉拱闭合胸法。这个模型最大的优点是能够在没有切割肋骨的情况下执行 TAC。手术创伤仅限于皮肤切口和肋间肌解剖。这一程序减少了创伤本身, 有助于保持足够的胸部稳定。
在这里, 我们描述了一个详细的分步程序, 以执行 TAC 手术在小鼠没有执行总或上开胸。高频多普勒用于确保 TAC 的成功, 如前所述6,7。

<table><tbody><tr><td>Pressure-volume catheter</td><td>Millar Instruments, USA</td><td>SPR-839</td><td></td></tr><tr><td>Mouse ventilator</td><td>Harvard Apparatus GmbH, Germany</td><td>Minivent - TYPE 845</td><td></td></tr><tr><td>Mouse ventilator</td><td>Harvard Apparatus GmbH, Germany</td><td>Y-connection with intubation cannula OD 1.2mm 73-2844</td><td></td></tr><tr><td>Vaporizer</td><td>Dr&amp;auml;ger Medical AG&amp;amp;CO.KG, Germany</td><td>19.3 Isofluran-Vaporizer (a newer version is available under catalog number&amp;nbsp; D-877-2010)</td><td></td></tr><tr><td>Microscope&amp;nbsp;</td><td>Leica Microsystems, Germany</td><td>MZ 7.5</td><td></td></tr><tr><td>Light source&amp;nbsp;</td><td>Schott AG, Germany</td><td>KL 1500 LCD</td><td></td></tr><tr><td>6-0 Prolene</td><td>Ethicon, USA</td><td>Polypropylene suture BV-1 9.3 mm 3/8c</td><td>suture for surgery</td></tr><tr><td>Seraflex</td><td>Serag Wiessner, Germany</td><td>USP 5/0 schwarz;&amp;nbsp; IC108000&amp;nbsp;</td><td>suture for constriction</td></tr><tr><td>Homoeothermic Controlled Operating Tables</td><td>Harvard Apparatus GmbH, Germany</td><td>Typ 872/3 HT with tripod stand and homoeothermic controller Type 874; 73-4233</td><td></td></tr><tr><td>Flexible Rectal Probe</td><td>Harvard Apparatus GmbH, Germany</td><td>1.6 mm OD; 55-7021</td><td></td></tr><tr><td>Doppler Signal Visualisation Instrument</td><td>Indus Instruments, USA</td><td>Doppler Signal Processing Workstation (DSWP) with 20MHz Pulsed Doppler Module</td><td></td></tr><tr><td>Arruga Intracapsular Forceps</td><td>Altomed, UK</td><td>A5400</td><td></td></tr><tr><td>Doppler Probe</td><td>Indus Instruments, USA</td><td>20MHz Tubing-mounted Probe</td><td></td></tr><tr><td>Jaffe Lid Retractor</td><td>Altomed, UK</td><td>A3513</td><td></td></tr></tbody></table>

a closed-chest model to induce transverse aortic constriction in mice

心肌肥厚和心力衰竭的研究往往是基于交谘会诱发的压力超负荷小鼠模型。标准程序是执行部分开胸术, 以可视化的横向主动脉弓。然而, 开胸模型切开术引起的手术创伤改变了肋骨解剖后的呼吸生理学, 胸部闭合后左不连接。为了防止这种情况, 我们通过侧开胸手术建立了一种微创, 闭合的胸部方法。在这里, 我们通过 2nd肋间空间接近主动脉弓, 而不进入胸腔, 使小鼠的外伤损伤恢复得更少。我们使用标准的实验室设置进行这项手术, 开放的胸腔交咨程序具有同等存活率。除了维持生理呼吸模式, 由于封闭的胸部方法, 小鼠似乎受益于显示快速恢复, 因为较少侵入技术似乎有助于快速愈合过程和减少免疫应答后的反应。

成功的交谘会保证压力超负荷和左心室肥厚的诱导。通过多普勒流速测量可以实现对压力过载的特别验证, 如图 2所示。虽然术前血流速度在两个颈动脉中均相等, 但交咨会由于左心室和主动脉升高的压力而导致右颈动脉增加的血流速, 同时导致狭窄后血流速度减弱。左颈动脉。
通过计算 C57BL/6J 雄性小鼠?...

Watch this Scientific Journal Video about A Closed-chest Model to Induce Transverse Aortic Constriction in Mice at JoVE.com

A Closed-chest Model to Induce Transverse Aortic Constriction in Mice

在这里, 我们提出一个横向主动脉收缩 (TAC) 通过侧开胸手术的协议。该技术是一种微创, 闭合胸部手术的过程, 旨在模拟压力超负荷和心力衰竭的小鼠使用标准的 TAC 实验室设置。

诱导小鼠横向主动脉狭窄的闭合胸模型

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to ...

a-closed-chest-model-to-induce-transverse-aortic-constriction-in-mice

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

18.8K 次观看.  University Hospital Bonn. 在这里, 我们提出一个横向主动脉收缩 (TAC) 通过侧开胸手术的协议。该技术是一种微创, 闭合胸部手术的过程, 旨在模拟压力超负荷和心力衰竭的小鼠使用标准的 TAC 实验室设置。

视频: A Closed-chest Model to Induce Transverse Aortic Constriction in Mice

The CYP2D6 Animal Model: How to Induce Autoimmune Hepatitis in Mice

Autoimmune hepatitis is a rare but life threatening autoimmune disease of the liver of unknown etiology1,2. In the past many attempts have been made to generate an animal model that reflects the characteristics of the human disease 3-5. However, in various models the induction of disease was rather complex and often hepatitis was only transient3-5. Therefore, we have developed a straightforward mouse model that uses the major human autoantigen in type 2 autoimmune hepatitis (AIH-2), namely hCYP2D6, as a trigger6. Type 1 liver-kidney microsomal antibodies (LKM-1) antibodies recognizing hCYP2D6 are the hallmark of AIH-27,8. Delivery of hCYP2D6 into wildtype FVB or C57BL/6 mice was by an Adenovirus construct (Ad-2D6) that ensures a direct delivery of the triggering antigen to the liver. Thus, the ensuing local inflammation generates a fertile field9 for the subsequent development of autoimmunity. A combination of intravenous and intraperitoneal injection of Ad-2D6 is the most effective route to induce a long-lasting autoimmune damage to the liver (section 1). Here we provide a detailed protocol on how autoimmune liver disease is induced in the CYP2D6 model and how the different aspects of liver damage can be assessed. First, the serum levels of markers indicating hepatocyte destruction, such as aminotransferases, as well as the titers of hCYP2D6 antibodies are determined by sampling blood retroorbitaly (section 2). Second, the hCYP2D6-specific T cell response is characterized by collecting lymphocytes from the spleen and the liver. In order to obtain pure liver lymphocytes, the livers are perfused by PBS via the portal vein (section 3), digested in collagen and purified over a Percoll gradient (section 4). The frequency of hCYP2D6-specific T cells is analyzed by stimulation with hCYP2D6 peptides and identification of IFN&gamma;-producing cells by flow cytometry (section 5). Third, cellular infiltration and fibrosis is determined by immunohistochemistry of liver sections (section 6). Such analysis regimen has to be conducted at several times after initiation of the disease in order to prove the chronic nature of the model. The magnitude of the immune response characterized by the frequency and activity of hCYP2D6-specific T and/or B cells and the degree of the liver damage and fibrosis have to be assessed for a subsequent evaluation of possible treatments to prevent, delay or abrogate the autodestructive process of the liver.

Infection of mice with an Adenovirus expressing the major human autoantigen cytochrome P450 2D6 (hCYP2D6) recognized by sera of patients suffering from type 2 autoimmune hepatitis results in a persistent form of autoimmune-mediated liver disease characterized by extensive hepatitis, fibrosis and generation of a CYP2D6-specific immune response.

CYP2D6动物模型：如何诱导小鼠自身免疫性肝炎

Autoimmune hepatitis is a rare but life threatening autoimmune disease of the liver of unknown etiology1,2. In the past many attempts have been made to ...

科研

医学

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 ...

Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart failure.1 TAC initially leads to compensated hypertrophy of the heart, which often is associated with a temporary enhancement of cardiac contractility. Over time, however, the response to the chronic hemodynamic overload becomes maladaptive, resulting in cardiac dilatation and heart failure.2 The murine TAC model was first validated by Rockman et al.1, and has since been extensively used as a valuable tool to mimic human cardiovascular diseases and elucidate fundamental signaling processes involved in the cardiac hypertrophic response and heart failure development. When compared to other experimental models of heart failure, such as complete occlusion of the left anterior descending (LAD) coronary artery, TAC provides a more reproducible model of cardiac hypertrophy and a more gradual time course in the development of heart failure. Here, we describe a step-by-step procedure to perform surgical TAC in mice. To determine the level of pressure overload produced by the aortic ligation, a high frequency Doppler probe is used to measure the ratio between blood flow velocities in the right and left carotid arteries.3, 4 With surgical survival rates of 80-90%, transverse aortic banding is an effective technique of inducing left ventricular hypertrophy and heart failure in mice.

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model to study mechanisms underlying cardiac hypertrophy and heart failure development. Here, we describe procedures to constrict the aorta to create a reproducible degree of cardiac hypertrophy in mice.

在小鼠体内的横向主动脉缩窄

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart ...

生物学

Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable noninvasive method is essential to assess real-time cardiac morphological and functional changes in animal models of heart disease. Transthoracic echocardiography represents an important tool for noninvasive assessment of cardiac structure and function2. Here we used a high-resolution ultrasound imaging system to monitor myocardial remodeling and heart failure progression over time in a mouse model of TAC. B-mode, M-mode, and Doppler imaging were used to precisely assess cardiac hypertrophy, ventricular dilatation, and functional deterioration in mice following TAC. Color and pulse wave (PW) Doppler imaging was used to noninvasively measure pressure gradient across the aortic constriction created by TAC and to assess transmitral blood flow in mice. Thus transthoracic echocardiographic imaging provides comprehensive noninvasive measurements of cardiac dimensions and function in mouse models of heart disease.

The goal of this protocol is to noninvasively assess cardiac structural and functional changes in a mouse model of heart disease created by transverse aortic constriction, using B- and M-mode echocardiography and color/pulse wave Doppler imaging.

在横向主动脉缩窄的小鼠模型和心脏形态学评估功能改变通过超声心动图成像

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

微创横向主动脉缩窄小鼠

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Technique of Minimally Invasive Transverse Aortic Constriction in Mice for Induction of Left Ventricular Hypertrophy

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure overload-induced left ventricular hypertrophy (LVH) and its progression to heart failure. In the majority of the reported investigations, this procedure is performed with intubation and ventilation of the animal which renders it demanding and time-consuming and adds to the surgical burden to the animal. The aim of this protocol is to describe a simplified technique of minimally invasive TAC without intubation and ventilation of mice. Critical steps of the technique are emphasized in order to achieve low mortality and high efficiency in inducing LVH.
Male C57BL/6 mice (10-week-old, 25-30 g, n=60) were anesthetized with a single intraperitoneal injection of a mixture of ketamine and xylazine. In a spontaneously breathing animal following a 3-4 mm upper partial sternotomy, a segment of 6/0 silk suture threaded through the eye of a ligation aid was passed under the aortic arch and tied over a blunted 27-gauge needle. Sham-operated animals underwent the same surgical preparation but without aortic constriction. The efficacy of the procedure in inducing LVH is attested by a significant increase in the heart/body weight ratio. This ratio is obtained at days 3, 7, 14 and 28 after surgery (n = 6 - 10 in each group and each time point). Using our technique, LVH is observed in TAC compared to sham animals from day 7 through day 28. Operative and late (over 28 days) mortalities are both very low at 1.7%.
In conclusion, our cost-effective technique of minimally invasive TAC in mice carries very low operative and post-operative mortalities and is highly efficient in inducing LVH. It simplifies the operative procedure and reduces the strain put on the animal. It can be easily performed by following the critical steps described in this protocol.

The aim of this protocol is to describe step-by-step the technique of minimally invasive transverse aortic constriction (TAC) in mice. By elimination of intubation and ventilation which are mandatory for the commonly used standard procedure, minimally invasive TAC simplifies the operative procedure and reduces the strain put on the animal.

小鼠横主动脉狭窄诱导左心室肥厚的技术研究

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure ...

Studying Left Ventricular Reverse Remodeling by Aortic Debanding in Rodents

To better understand the left ventricular (LV) reverse remodeling (RR), we describe a rodent model wherein, after aortic banding-induced LV remodeling, mice undergo RR upon removal of the aortic constriction. In this paper, we describe a step-by-step procedure to perform a minimally invasive surgical aortic debanding in mice. Echocardiography was subsequently used to assess the degree of cardiac hypertrophy and dysfunction during LV remodeling and RR and to determine the best timing for aortic debanding. At the end of the protocol, terminal hemodynamic evaluation of the cardiac function was conducted, and samples were collected for histological studies. We showed that debanding is associated with surgical survival rates of 70-80%. Moreover, two weeks after debanding, the significant reduction of ventricular afterload triggers the regression of ventricular hypertrophy (~20%) and fibrosis (~26%), recovery of diastolic dysfunction as assessed by the normalization of left ventricular filling and end-diastolic pressures (E/e&#39;&#160;and LVEDP). Aortic debanding is a useful experimental model to study LV RR in rodents. The extent of myocardial recovery is variable between subjects, therefore, mimicking the diversity of RR that occurs in the clinical context, such as aortic valve replacement. We conclude that the aortic banding/debanding model represents a valuable tool to unravel novel insights into the mechanisms of RR, namely the regression of cardiac hypertrophy and the recovery of diastolic dysfunction.

Here we describe a step-by-step protocol of surgical aorta debanding in the well-established mice model of aortic-constriction. This procedure not only allows studying the mechanisms underlying the left ventricular reverse remodeling and regression of hypertrophy but also to test novel therapeutic options that might accelerate myocardial recovery.

研究左心室反向改造由主动脉脱体在啮齿动物

To better understand the left ventricular (LV) reverse remodeling (RR), we describe a rodent model wherein, after aortic banding-induced LV remodeling, ...

Operating Transverse Aortic Constriction with Absorbable Suture to Obtain Transient Myocardial Hypertrophy

Based on twice transverse aortic constrictions (TACs) in mice, it is proved that myocardial hypertrophic preconditioning (MHP) could attenuate cardiomyocyte hypertrophy and slow down progression to heart failure. For novices, however, the MHP model is usually quite difficult to establish because of the technical obstacles in ventilator operation, opening the chest repeatedly, and bleeding caused by debanding. To facilitate this model, to increase the surgical success rate and to reduce the incidence of bleeding, we switched to absorbable sutures for the first TAC combing with a ventilator-free technique. Using a 2-week absorbable suture, we demonstrated that this procedure could cause significant myocardial hypertrophy in 2 weeks; and 4 weeks after surgery, myocardial hypertrophy was almost completely regressed to the baseline. Using this protocol, the operators could master the MHP model easily with a lower operation mortality.

This protocol presents an improved method to obtain transient myocardial hypertrophy with absorbable suture, simulating left ventricular hypertrophy decrease after removing pressure overload. It could be valuable for the studies on myocardial hypertrophic preconditioning.

操作横向主动脉收缩与可吸收的缝合获得瞬时心肌萎缩

Based on twice transverse aortic constrictions (TACs) in mice, it is proved that myocardial hypertrophic preconditioning (MHP) could attenuate ...

A Modified Technique for Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of pressure overload in mouse models. The main challenge of this procedure is to clearly visualize the transverse aortic arch and precisely band the target vessel. Classical approaches perform a partial thoracotomy to expose the transverse aortic arch. However, it is an open-chest model that causes a rather large surgical trauma and requires a ventilator during the surgery. To prevent unnecessary trauma and simplify the operating procedure, the aortic arch is approached via the proximal proportion of the sternum, reaching and binding the target vessel using a small self-made retractor that contains a snare. This procedure can be conducted without entering the pleura cavity and does not need a ventilator or microsurgical operation, which leaves the mice with physiological breathing patterns, simplifies the procedure, and significantly reduces operation time. Due to the less invasive approach and less operation time, mice can undergo fewer stress reactions and recover rapidly.

The present protocol describes a modified and simplified technique with a minimally invasive transverse aortic constriction (TAC) procedure using a self-made retractor. This procedure can be conducted without a ventilator or microscope and introduces pressure overload, eventually leading to cardiac hypertrophy or heart failure.

一种改良的小鼠横主动脉收缩技术

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of ...

Transverse Aortic Arch Banding in Mouse Model: A Minimally Invasive Technique in Mice for Induction of High Pressure in the Left Ventricle

Source: Zaw, A. M. et al. <a href="https://jove.unicartagenaproxy.elogim.com/video/55293" target="_blank">Minimally Invasive Transverse Aortic Constriction in Mice</a>. J. Vis. Exp. (2017)
In this video, we demonstrate an experimental protocol for minimally invasive transverse aortic constriction in mice to examine pressure overload-induced heart failure.

小鼠横主动脉弓条带模型:小鼠诱导左心室高压的微创技术

Source: Zaw, A. M. et al. Minimally Invasive Transverse Aortic Constriction in Mice. J. Vis. Exp. (2017)
In this video, we demonstrate an experimental ...