描述该项目奖号码R01 HL064761，R25 HL059868 1SC1 HL099139和P20 MD000175形式国立卫生研究院的支持。内容完全是作者的责任，并不一定代表国立卫生研究院的官方意见。

1。分离大鼠肠系膜小动脉<ol><li>麻醉与异氟醚在一个封闭的腔的动物，并用酒精擦拭腹部。 </li><li>执行行剖腹探查术中暴露肠系膜床。 </li><li>用剪刀，除去约85厘米的肠道喂养与肠系膜上动脉血管。切割近端肠道部分接近幽门和末端回肠coecal交界附近。部分小肠被隔离的大鼠，深感麻醉与异氟醚和开胸心脏穿刺安乐死。 </li><li>涂层的培养皿含PSS的菜摆在切除部分和肠系膜上动脉，在室温下进行清扫。 </li><li>拖住右侧近端肠道和引脚intestineina反时针方向的其余部分（ieproximal远侧肠腔内的左喂养血管结束）。 </li><li>解剖分支II和III段加上了一块近段。 </li><li>解剖出的静脉和隔离动脉（V形分支点），清洁去除脂肪和结缔组织。用镊子轻轻拉动，并通过膜的结缔组织切割，避免直接接触与动脉。 </li></ol> 2。安装的船只<ol><li>切两短段的一个40微米的钨不锈钢丝（≈4厘米），并用细镊子，插入到每个照顾不损伤血管内皮细胞的动脉管腔之一。使用导线尖端打开管腔，如果必要的。血液流的船只是一个好兆头，管腔打开。 </li><li>填写与生理盐溶液（PSS肌动描记室; MM：115氯化钠，碳酸氢钠，1.2 K 2 HPO 4，1.1 1.4 4.7氯化钾，硫酸镁4 .7 H 2 O，5 NA 2 HPO 4，1.0氯化钙 ，20 HEPES 5葡萄糖，pH值7.4与抗坏血酸（100μM））在37 ° C，使用镊子小心从培养皿转移螺纹血管段在室温室和转让切除近端血管段的肌动描记室和拉结束沿导线送入血管。避免伸展船只。 </li><li>安全下连接到微米的右侧下颚附近的固定螺丝逆时针线附近结束。赶上与钳线自由端和安全远在右侧下颚固定螺丝顺时针。确保不作出任何颌骨本身联系的情况下，沿着电线的血管段位于颌骨之间的差距。 </li><li>螺杆颌骨外，船只第二线平行对齐，插入远端管腔。轻轻送入血管段的管腔一个使用已安装的电线为指导的议案的电线。容纳约1厘米的容器，以避免拉伸过程中的回旋线，并避免接触血管内皮细胞。 </li><li>螺杆颌骨和确保第二安装线下的第一个移动的右侧下颚担保。 </li><li>保护下的传感器连接到左侧下颚附近的固定螺丝以顺时针方向第二线的近端。 </li><li>下的左手颌骨上的固定螺丝固定电线的尽头，并拧紧拉伸导线。 </li><li>一旦安装完成后，在“安装菜单”复位电机和船只开始正常化。 </li></ol> 3。正常化的自动双丝肌动描记系统- 510A有一个自动正常化的功能，这是从的“正常化”菜单评估，并允许船只被拉长到一个规范化的内部周长，标准化的程序为30分钟，平衡后根据制造商的协议37 ° C。指数曲线，然后安装到内部的圆周压力数据。该程序定义在体内有动脉时放松透了1 100毫米汞柱压力下，管腔直径（D 100）大鼠肠系膜动脉的正常化参数如下： <ol><li>目标透压力= 13.3千帕（100毫米汞柱）。 </li><li>时间= 60秒;每个正常化的步骤的持续时间。 </li><li>芯片的1 / IC 100 = 0.9（IC 1 =正常化内部围，IC 100 =内部周长对应目标的压力。 </li><li>目镜校正2 *Δ（毫米/眼师）; 2三角洲是编程的原因。 </li></ol>测量使用显微镜的目镜读数时细线远，近两端安装的船只SEGM安装肠系膜动脉的长度ENT。简单地说，安装的血管段的长度测量与校准眼眼片，在解剖镜下的最大放大倍率。阅读过远段结束（1）眼片的发线和眼师（2）段的近端测量和记录。这些值，用千分尺的读数，前后伸缩的船只被记录下来，并进入到程序的菜单来计算拟合曲线和相应的内部直径100毫米汞柱的目标透压力在我们的研究中，动脉管腔直径D 1 = 0.9 XD 100，其中的积极力量的发展是最大的。大鼠肠系膜动脉≥10分钟的积极力量，在发展被认为是最佳的实验进行。较低的积极力量组织被丢弃。 4。测量的反应正常化后，船只，机械和功能特性被重新激活，执行“标准开始”，其中包括与反复应用的苯肾上腺素（PE）5微米（一般为2或3）具有挑战性的船只获得重复性收缩。一个典型的“标准开始”在我们的实验室包括了一系列刺激如下冲刷时期： <ol><li>替换肌动描记室盖和95％的空气和5％的CO 2开始曝气。 </li><li>填写室与新鲜PSS的（含100μM的抗坏血酸） </li><li>合同船只5微米聚乙烯为5分钟，并与PSS的缓冲液洗4次。 </li><li>经过最后一次洗涤，笔芯与PSS室，等待3分钟，然后重复步骤（二）及（iii）。 </li></ol>标准启动后，动脉为实验做好准备。评估累计此外氯化钙浓度的增加（0.5 - 4毫米）收缩血管的松弛。当使用抑制剂的船只前培养与肌动描记20分钟，目前在检测室的化合物。 5。数据分析 “正常化”船只和力量追查，直接转换成文本数据的数据进行了分析与SigmaPlot 11.0绘图程序（SYSTAT软件，点里士满，CA），并绘制成图1所示。浓度反应的数据，从描计算，分析，确定一个在程序药理菜单中的四个参数logistic函数拟合实验数据的EC 50值。组间和组内比较进行了方差分析（ANOVA），P &lt;0.05被认为是显著的差异。 6。代表性的成果： <table border="1"><tbody><tr><th>参数</th><th>只Wistar </th><th> Dahl盐敏感</th><th> Dahl盐抗</th></tr><tr><td> L 100（微米） </td><td> 83.26 ± 2.33 </td><td> 91.52 ± 4.67 </td><td> 117.45 ± 8.43 * </td></tr><tr><td> X 1 </td><td> 604.21 ± 41.97 </td><td> 752.24 ± 85.25 </td><td> 745.84 ± 110.09 </td></tr><tr><td> R 2 </td><td> 0.99 ± 0.003 </td><td> 0.97 ± 0.008 </td><td> 0.97 ± 0.007 </td></tr></tbody></table> * Wistar和DR L 100值之间的差异有统计学意义 。 夏皮罗-威尔克常态测试通过（P = 0.588）;通过平等方差检验（P = 0.237）。 L 100 =安装段对应的目标透压力内部直径。 × 1 =伸展式船只规范化的内部周长（即实验的千分尺读数值）所需的微定位设置。 R 2 =拟合回归系数（X I，Y I）指数曲线。 注：510A肌动描记器系统6手册中所描述的详细过程。 表1样本读出从“正常化菜单”中显示的基本程序只Wistar，DS和DR的肠系膜动脉段正常化参数。价值观是指（± SEM）的5只动物。 * L 100值之间的差异Wistar和DS统计学意义（P &lt;0.05）。 <table border="1"><tbody><tr><th>只Wistar </th><th>局副局长</th><th>议员</th></tr><tr><td> 14.2 ± 0.6 </td><td><strong&gt; 25.8 ± 2.7 * </td><td> 20.9 ± 1.3 * </td></tr></tbody></table> 表2。紧张局势（MN）在只Wistar，DS和DR大鼠分离的肠系膜动脉，以下5微米PE每艘船舶的申请。报告的值是指（± SEM）的6-8动物。 *显着不同只Wistar控制（P &lt;0.05）。 <img alt="图1" src="/files/ftp_upload/3119/3119fig1.jpg" /> 图1的Ca 2 + E -诱导放宽承包的PE从Wistar大鼠肠系膜动脉安装在生理盐溶液中含1毫米的Ca 2 +在丝肌动描记。动脉30分钟的平衡，在37 ° C的恒定曝气反应的Ca 2 + E决定。代表队另外5微米PE累计增加钙的跟踪 +所示。 <img alt="图2" src="/files/ftp_upload/3119/3119fig2.jpg" /> 图2的Ca 2 + E -诱导放宽承包一个PE从DS大鼠肠系膜动脉安装在生理盐溶液中含1毫米的Ca 2 +在丝肌动描记。动脉30分钟的平衡，在37 ° C的恒定曝气反应的Ca 2 + E决定。代表队另外5微米PE累计增加钙的跟踪 +所示。的Ca 2 +松弛，严重损害这个组织相比，那些来自Wistar和DR大鼠。 <img alt="图3" src="/files/ftp_upload/3119/3119fig3.jpg" /> 图3的Ca 2 + E -诱导放宽承包的PE从DR大鼠肠系膜动脉安装在生理盐溶液中含1毫米的Ca 2 +在丝肌动描记。动脉平衡30分钟，在37 ° C的恒定曝气反应的Ca 2 + E determined.A代表力量追查另外5微米PE累计增加钙+所示。 <img alt="图4" src="/files/ftp_upload/3119/3119fig4.jpg" /> 图4。 A.的[Ca 2 +] E -响应曲线。条形图显示EC 50放松，通过数据拟合四个参数在DR和DS大鼠分离的肠系膜商场后勤curve.C.CaR表达确定的值。

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高血压是心血管，脑和肾脏的发病率/死亡率的首要原因。高血压的发生是在人口高盐敏感性高血压是特别高，在人口老龄化，更多的黑人比白人流行。这被认为是由于对黑人的倾向保留在自己的肾脏 9钠。盐敏感性是肾脏疾病的一个主要因素，并与血管内皮功能障碍有关，但机制尚不完全清楚。在我们实验室最近的研究显示，高盐饮食可减少组织间液的Ca 2 +浓度（[Ca2 2 <su...

<table border="1"><tbody><tr><th>设备名称/试剂</th><th>公司</th><th>目录编号</th><th>评论（可选） </th></tr><tr><td>自动双丝肌动描记系统- 510A DMT美国公司</td><td>佐治亚州亚特兰大。 </td><td> 100151 </td><td></td></tr><tr><td> PowerLab/4SP数据采集系统</td><td> ADInstruments，科罗拉多州的斯普林斯，CO </td><td> ML750 </td><td> 4-16输入通道的新车型。 </td></tr><tr><td>戴尔Dimension XPS第四代计算机</td><td>戴尔</td><td></td><td></td></tr><tr><td> STEMI SV二（APO）与眼的解剖显微镜</td><td>国际卡尔蔡司。 </td><td></td><td></td></tr><tr><td>只Wistar，Dahl盐敏感，Dahl盐抵抗大鼠</td><td>哈伦只Dawley，印第安纳波利斯，IN。 </td><td></td><td></td></tr><tr><td>鼠类议员</td><td>哈兰德Tekland，麦迪逊，威斯康星州。 </td><td></td><td></td></tr><tr><td>去氧</td><td> Sigma - Aldrich公司，圣路易斯，密苏里州。 </td><td></td><td></td></tr><tr><td>其他化学品</td><td></td><td></td><td>所有使用的化学品是最纯净的成绩可以买到。 </td></tr></tbody></table>

mesenteric artery contraction and relaxation studies using automated wire myography

如肠系膜动脉的近端阻力血管，作出重大贡献的外周阻力。这些小血管的功能，主要是在指挥根据到身体的总体要求各个器官的血流量，直径100-400微米之间。大鼠肠系膜动脉的直径大于100微米的。贝文和奥谢尔2所提出的方法的基础上，首先由 1 Mulvay和哈尔彭所描述的，是myography技术。该技术提供等距条件下，大幅缩短的肌肉准备阻止的小型船只的信息。由于力的生产和船只不同受体激动剂的敏感性依赖于伸展的程度，按照积极紧张长度关系，这是必不可少的等距条件下进行收缩的研究，以防止符合安装电线。不锈钢丝是首选，因为后者的氧化，从而影响记录反应3钨丝，该技术允许安装船只激动剂诱导的收缩比较，以获取证据表明血管平滑肌细胞受体的正常功能。 在几项研究中，我们已经表明phenylyephrine承包的，孤立的肠系膜动脉累积浓度的钙（钙2 + E）除了放宽。结果导致我们得出结论，它表达的G蛋白偶联的Ca 2 +敏感受体（CAR），血管周围的感官神经，调解这个血管舒张反应。使用自动线myography方法，我们在这里展示，从只Wistar Dahl盐敏感（DS）和Dahl盐抵抗（DR）的肠系膜动脉的大鼠有不同的反应的Ca 2 + E 。从大鼠组织表现出更高的Ca 2 +敏感性相比，DR和DS。减少从DS大鼠肠系膜动脉车表达与减少的Ca 2 + E -诱导孤立的，承包前动脉松弛。数据表明，汽车是需要放宽增加肾上腺素基调下肠系膜动脉，在高血压发生，并表示在汽车的信号转导通路在达尔动物的固有缺陷，这是更为严重的DS。 肠系膜阻力动脉和类似的小血管和比较不同的受体激动剂和/或拮抗剂在确定血管反应性的体外的方法是有用的，可以很容易地和一贯的评估并排侧6,7,8。

Watch this Scientific Journal Video about Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography at JoVE.com

Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography

一个孤立的肠系膜动脉的力测量的自动化myography方法描述。它采用一个Mulvany哈尔彭自动双丝肌动描记510A福林和钙，以确定响应。该方法允许等距反应一致，以激动剂决心在小血管的直径为60 - 300微米，独立。

肠系膜动脉收缩和舒张的研究，使用自动线Myography

Proximal resistance vessels, such as the mesenteric arteries, contribute substantially to the peripheral resistance. These small vessels of between ...

mesenteric-artery-contraction-relaxation-studies-using-automated-wire

Research

JoVE Journal

Medicine

28.4K 次观看.  North Carolina Central University, Durham. 一个孤立的肠系膜动脉的力测量的自动化myography方法描述。它采用一个Mulvany哈尔彭自动双丝肌动描记510A福林和钙，以确定响应。该方法允许等距反应一致，以激动剂决心在小血管的直径为60 - 300微米，独立。

视频: Mesenteric Artery Contraction and Relaxation Studies Using Automated Wire Myography

Assessing Myogenic Response and Vasoactivity In Resistance Mesenteric Arteries Using Pressure Myography

Small resistance arteries constrict and dilate respectively in response to increased or decreased intraluminal pressure; this phenomenon known as myogenic response is a key regulator of local blood flow. In isobaric conditions small resistance arteries develop sustained constriction known as myogenic tone (MT), which is a major determinant of systemic vascular resistance (SVR). Hence, ex vivo&#160;pressurized preparations of small resistance arteries are major tools to study microvascular function in near-physiological states. To achieve this, a freshly isolated intact segment of a small resistance artery (diameter ~260 &#956;m) is mounted onto two small glass cannulas and pressurized. These arterial preparations retain most in vivo characteristics and permit assessment of vascular tone in real-time. Here we provide a detailed protocol for assessing vasoactivity in pressurized small resistance mesenteric arteries from rats; these arteries develop sustained vasoconstriction - approximately 25% of maximal diameter - when pressurized at 70 mmHg. These arterial preparations may be used to study the effect of investigational compounds on relationship between intra-arterial pressure and vasoactivity and determine changes in microvascular function in animal models of various diseases.

Pressure myography is used to assess vasoactivity of small arteries that develop sustained constriction when pressurized. This manuscript provides a detailed protocol to assess in isolated segments of small mesenteric arteries from rats, vasoactivity and the effect of intraluminal pressure on vascular diameter.

评估肌反应及血管活性阻力肠系膜动脉使用压力肌动描记

Small resistance arteries constrict and dilate respectively in response to increased or decreased intraluminal pressure; this phenomenon known as myogenic ...

科研

医学

Isolating and Using Sections of Bovine Mesenteric Artery and Vein as a Bioassay to Test for Vasoactivity in the Small Intestine

Mammalian gastrointestinal systems are constantly exposed to compounds (desirable and undesirable) that can have an effect on blood flow to and from that system. Changes in blood flow to the small intestine can result in effects on the absorptive functions of the organ. Particular interest in toxins liberated from feedstuffs through fermentative and digestive processes has developed in ruminants as an area where productive efficiencies could be improved. The video associated with this article describes an in vitro bioassay developed to screen compounds for vasoactivity in isolated cross-sections of bovine mesenteric artery and vein using a multimyograph. Once the blood vessels are mounted and equilibrated in the myograph, the bioassay itself can be used: as a screening tool to evaluate the contractile response or vasoactivity of compounds of interest; determine the presence of receptor types by pharmacologically targeting receptors with specific agonists; determine the role of a receptor with the presence of one or more antagonists; or determine potential interactions of compounds of interest with antagonists. Through all of this, data are collected real-time, tissue collected from a single animal can be exposed to a large number of different experimental treatments (an in vitro advantage), and represents vasculature on either side of the capillary bed to provide an accurate picture of what could be happening in the afferent and efferent blood supply supporting the small intestine.

The small intestine is frequently exposed to toxins that can influence blood flow and negatively impact nutrient absorption. Using a multimyograph and mesenteric artery and vein isolates, compounds or toxins of interest can be screened for vasoactivity.

隔离和使用的牛肠系膜动脉和静脉部分，作为生物测定在小肠测试的Vasoactivity

Mammalian gastrointestinal systems are constantly exposed to compounds (desirable and undesirable) that can have an effect on blood flow to and from that ...

Murine Model of Femoral Artery Wire Injury with Implantation of a Perivascular Drug Delivery Patch

Percutaneous interventions including balloon angioplasty and stenting have been used to restore blood flow in vessels with occlusive vascular disease. While these therapies lead to the rapid restoration of blood flow, these technologies remain limited by restenosis in the case of bare metal stents and angioplasty, or reduced healing and possibly enhanced risk of thrombosis in the case of drug eluting stents. A key pathophysiological mechanism in the formation of restenosis is intimal hyperplasia caused by the activation of vascular smooth muscle cells and inflammation due to arterial stretch and injury. Surgeries that induce arterial injury in genetically modified mice are useful for the mechanistic study of the vascular response to injury but are often technically challenging to perform in mouse models due to the their small size and lack of appropriate sized devices. We describe two approaches for a surgical technique that induces endothelial denudation and arterial stretch in the femoral artery of mice to produce robust neointimal hyperplasia. The first approach creates an arteriotomy in the muscular branch of the femoral artery to obtain vascular access. Following wire injury this arterial branch is ligated to close the arteriotomy. A second approach creates an arteriotomy in the main femoral artery that is later closed through localized cautery. This method allows for vascular access through a larger vessel and, consequently, provides a less technically demanding procedure that can be used in smaller mice. Following either method of arterial injury, a degradable drug delivery patch can be placed over or around the injured artery to deliver therapeutic agents.

We describe a surgical technique that produces wire injury in the femoral artery of mice to induce neointimal hyperplasia to serve as a model testing system for the perivascular delivery of therapeutic compounds for the inhibition of restenosis.

股动脉线损伤的小鼠模型的血管周围给药补丁植入

Percutaneous interventions including balloon angioplasty and stenting have been used to restore blood flow in vessels with occlusive vascular disease. ...

A Murine Model of Arterial Restenosis: Technical Aspects of Femoral Wire Injury

Cardiovascular disease caused by atherosclerosis is the leading cause of death in the developed world. Narrowing of the vessel lumen, due to atherosclerotic plaque development or the rupturing of established plaques, interrupts normal blood flow leading to various morbidities such as myocardial infarction and stroke. In the clinic endovascular procedures such as angioplasty are commonly performed to reopen the lumen. However, these treatments inevitably damage the vessel wall as well as the vascular endothelium, triggering an excessive healing response and the development of a neointimal plaque that extends into the lumen causing vessel restenosis (re-narrowing). Restenosis remains a major cause of failure of endovascular treatments for atherosclerosis. Thus, preclinical animal models of restenosis are vitally important for investigating the pathophysiological mechanisms as well as translational approaches to vascular interventions. Among several murine experimental models, femoral artery wire injury is widely accepted as the most suitable for studies of post-angioplasty restenosis because it closely resembles the angioplasty procedure that injures both endothelium and vessel wall. However, many researchers have difficulty utilizing this model due to its high degree of technical difficulty. This is primarily because a metal wire needs to be inserted into the femoral artery, which is approximately three times thinner than the wire, to generate sufficient injury to induce prominent neointima. Here, we describe the essential surgical details to effectively overcome the major technical difficulties of this model. By following the presented procedures, performing the mouse femoral artery wire injury becomes easier. Once familiarized, the whole procedure can be completed within 20 min.

The mouse femoral artery wire injury model of restenosis is technically challenging. In this protocol we show the key technical details essential for successfully performing wire injury to induce consistent&#160;neointima for studies of restenosis.

动脉再狭窄小鼠模型：股导线损伤的技术方面

Cardiovascular disease caused by atherosclerosis is the leading cause of death in the developed world. Narrowing of the vessel lumen, due to ...

Induction of Accelerated Atherosclerosis in Mice: The "Wire-Injury" Model

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. Moreover, by rupture of the defective vascular wall, atherosclerosis induces occlusive thrombus formation, which represents the main cause of myocardial infarction or stroke and the most frequent cause of death. Despite the advances in the cardiovascular field, many questions remain unanswered, and additional basic research is essential to improve our understanding of the molecular mechanisms during atherosclerosis and its effects. Due to limited clinical studies, there is a need for representative animal models recreating atherosclerotic conditions such as neointima formation after stent implantation, balloon angioplasty, or endarterectomy. Since the mouse presents many advantages and is the most frequently used model for studying molecular processes, the current study proposes an invasive procedure of endothelial denudation, also known as the wire-injury model, which is representative of the human condition of neointima formation in arteries after revascularization procedures.

Induction of Accelerated Atherosclerosis in Mice: The &quot;Wire-Injury&quot; Model

This study describes an invasive procedure for the induction of accelerated atherosclerosis in mice. In comparison to other methods using electric- or cryo-induced injury, mechanical-induced injury mimics the human condition of restenosis after revascularization therapies and is ideal for the study of the molecular mechanisms involved.

小鼠加速动脉硬化的诱导："电线损伤"模型

Atherosclerosis is a proliferative fibro-inflammatory disease developing in the arterial wall, inducing a deficient blood flow or a lack of blood flow. ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

用线 Myography 测定小鼠肠系膜动脉的等轴收缩力

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Model of Ischemic Heart Disease and Video-Based Comparison of Cardiomyocyte Contraction Using hiPSC-Derived Cardiomyocytes

Ischemic heart disease is a significant cause of death worldwide. It has therefore been the subject of a tremendous amount of research, often with small-animal models such as rodents. However, the physiology of the human heart differs significantly from that of the rodent heart, underscoring the need for clinically relevant models to study heart disease. Here, we present a protocol to model ischemic heart disease using cardiomyocytes differentiated from human induced pluripotent stem cells (hiPS-CMs) and to quantify the damage and functional impairment of the ischemic cardiomyocytes. Exposure to 2% oxygen without glucose and serum increases the percentage of injured cells, which is indicated by staining of the nucleus with propidium iodide, and decreases cellular viability. These conditions also decrease the contractility of hiPS-CMs as confirmed by displacement vector field analysis of microscopic video images. This protocol may furthermore provide a convenient method for personalized drug screening by facilitating the use of hiPS cells from individual patients. Therefore, this model of ischemic heart disease, based on iPS-CMs of human origin, can provide a useful platform for drug screening and further research on ischemic heart disease.

We present a model of ischemic heart disease using cardiomyocytes derived from human induced pluripotent stem cells, together with a method for quantitative evaluation of tissue damage caused by ischemia. This model can provide a useful platform for drug screening and further research on ischemic heart disease.

使用hiPSC衍生心肌细胞的缺血性心脏病模型和基于视频的心肌细胞收缩比较

Ischemic heart disease is a significant cause of death worldwide. It has therefore been the subject of a tremendous amount of research, often with ...

Mechanical Control of Relaxation Using Intact Cardiac Trabeculae

Diastolic dysfunction is a common phenotype across cardiovascular disease presentations. In addition to elevated cardiac stiffness (elevated left ventricular end-diastolic pressure), impaired cardiac relaxation is a key diagnostic indicator of diastolic dysfunction. While relaxation requires the removal of cytosolic calcium and deactivation of sarcomeric thin filaments, targeting such mechanisms has yet to provide effective treatments. Mechanical mechanisms, such as blood pressure (i.e., afterload), have been theorized to modify relaxation. Recently, we showed that modifying the strain rate of a stretch, not afterload, was both necessary and sufficient to modify the subsequent relaxation rate of myocardial tissue. The strain rate dependence of relaxation, called the mechanical control of relaxation (MCR), can be assessed using intact cardiac trabeculae. This protocol describes the preparation of a small animal model, experimental system and chamber, isolation of the heart and subsequent isolation of a trabecula, preparation of the experimental chamber, and experimental and analysis protocols. Evidence for lengthening strains in the intact heart suggests that MCR might provide new arenas for better characterization of pharmacological treatments, along with a method to assess myofilament kinetics in intact muscles. Therefore, studying the MCR may elucidate a path to novel approaches and new frontiers in the treatment of heart failure.

Rapid myocardial and cardiac relaxation is essential for normal physiology. Mechanical relaxation mechanisms are now known to be dependent on strain rate. This protocol provides an overview of the acquisition and analysis of experiments to further study the mechanical control of relaxation.

使用完整的心脏小梁机械控制松弛

Diastolic dysfunction is a common phenotype across cardiovascular disease presentations. In addition to elevated cardiac stiffness (elevated left ...

Multimodality Diagnosis of Mesenteric Ischemia

Early diagnosis of mesenteric ischemia remains challenging because mesenteric ischemia presents with no key symptoms or physical findings, and no laboratory data specifically indicates intestinal tissue ischemic status before necrosis develops. While computed tomography is the standard for diagnostic imaging, there are several limitations: (1) repeated assessments are associated with increased radiation exposure and risk of renal damage; (2) the computed tomography findings can be misleading because necrosis occasionally occurs despite opacified mesenteric arteries; and (3) computed tomography is not necessarily available within the golden time of salvaging the intestines for those patients in the operating room or at a place far from the hospital. This article describes a challenge to overcome such limitations using ultrasonography and near-infrared light, including clinical studies. The former is capable of providing not only morphologic and kinetic information of the intestines but also perfusion of the mesenteric vessels in real-time without transferring the patient or exposing them to radiation. Transesophageal echocardiography enables precise assessment of mesenteric perfusion in the OR, ER, or ICU. Representative findings of mesenteric ischemia in seven aortic dissection cases are presented. Near-infrared imaging with indocyanine green helps visualize the perfusion of vessels and intestinal tissues although this application requires laparotomy. Findings in two cases (aortic aneurysm) are shown. Near-infrared spectroscopy demonstrates oxygen debt in the intestinal tissue as digital data and can be a candidate for early detection of mesenteric ischemia without laparotomy. The accuracy of these assessments has been confirmed by intraoperative inspections and postoperative course (prognosis).

This article presents a multimodal approach that aims to overcome the limitations of traditional methods in detecting mesenteric ischemia and preventing bowel necrosis. The presented technique offers a promising solution by combining state-of-the-art ultrasonography with cutting-edge near-infrared light technologies.

肠系膜缺血的多模式诊断

Early diagnosis of mesenteric ischemia remains challenging because mesenteric ischemia presents with no key symptoms or physical findings, and no ...

Rodent Model of Intestinal Ischemia-Reperfusion Injury via Occlusion of the Superior Mesenteric Artery

Intestinal ischemia-reperfusion injury (IRI) is associated with a myriad of conditions in both veterinary and human medicine. Intestinal IRI conditions, such as gastric dilatation volvulus (GDV), mesenteric torsion, and colic, are observed in animals such as dogs and horses. An initial interruption of blood flow causes tissues to become ischemic. Although necessary to salvage viable tissue, subsequent reperfusion can induce further injury. The main mechanism responsible for IRI is free radical formation upon reperfusion and reintroduction of oxygen into damaged tissue, but there are many other components involved. The resulting local and systemic effects often impart a poor prognosis. 
Intestinal IRI has been the subject of extensive research over the past 50 years. An in vivo rodent model in which the base of the superior mesenteric artery (SMA) is temporarily ligated is currently the most common method used to study intestinal IRI. Here, we describe a model of intestinal IRI utilizing isoflurane anesthesia in 21% O2 medical air that yields reproducible injury, as demonstrated by consistent histopathology of the small intestines. Tissue injury was also assessed in the colon, liver, and kidneys.

We describe how to generate a widely used surgical model of intestinal ischemia-reperfusion injury (IRI) in rodents. The procedure involves occlusion of the superior mesenteric artery followed by the restoration of blood flow. This model is useful for studies investigating occlusive causes of intestinal IRI in both veterinary and human medicine.

肠系膜上动脉闭塞的肠缺血再灌注损伤的啮齿动物模型

Intestinal ischemia-reperfusion injury (IRI) is associated with a myriad of conditions in both veterinary and human medicine. Intestinal IRI conditions, ...