Name: ultrasound assessment of flow-mediated dilation of the brachial and superficial femoral arteries in rats
Uploaded: 2016-11-03T13:00:00.000+00:00
Duration: 9 min 40 s
Description: Watch this Scientific Journal Video about Ultrasound Assessment of Flow-Mediated Dilation of the Brachial and Superficial Femoral Arteries in Rats at JoVE.com

All animal imaging was performed at the Small Animal Imaging Core Facility, University of Utah.
This study was funded in part by grants from the National Institutes of Health (R21 AG043952, R01 AG040297, K01 AG046326, K02 AG045339, and R01 DK100505).

所有动物的程序符合指南实验动物14的管理和使用以及犹他州大学和盐湖城的退伍军人医疗中心动物护理和使用获得批准。 1.动物的制备<ol><li>将动物含100％氧气3％异氟醚麻醉诱导室。留在感应室中的动物，直到它响应外部刺激。 </li><li>从感应腔室取出动物，并将其放置在配备有心电图（ECG）电极加热的检查表。维持在100％的氧气3％异氟醚麻醉。肱动脉和股浅动脉FMD不能同时进行。因此，对于每个测定准备指令在下面列出。 </li></ol> 2.肱动脉准备<ol><li>放置动物仰卧，抑制左上肢和一个各下肢进制与手术磁带的体检表。 </li><li>抑制动物的右上肢，使上肢的下部略微升高的平台之上（〜0.2-0.5厘米）。 </li><li>应用脱毛剂（如奈尔），以动物的右上肢去除毛发。 </li><li>定位在右上肢远端的肘闭塞箍（10毫米管腔直径标准血管阻塞）。不休息平台上的封堵器，因为通胀/通缩将移动肢体，扰乱超声图像。 </li><li>使用超声波键盘的超声波机器设置为B型。 </li><li>应用超声凝胶的少量动物，近端闭塞箍的上肢。 </li><li>手动对齐附着到立体支架与上肢的超高频线性阵列换能器。肱动脉应该是可见2-3毫米深。 </li><li>以确认肱动脉，不肱静脉，正在成像，切换到使用超声波键盘PW-模式。动脉将脉动血流，而不是这将有连续血流相邻静脉。 </li></ol> 3，股浅动脉准备<ol><li>定位动物仰卧和抑制上肢和左下肢到检查台与手术胶带。 </li><li>抑制动物的右下肢到升高位置（〜0.5-1厘米），使用垫（例如，折叠的纸巾）的平台之上。 </li><li>应用脱毛剂（如奈尔），以动物的右下肢去除毛发。脱毛后股静脉应在上内大腿清晰可见。 </li><li>位置的闭塞套（10毫米管腔直径标准血管封堵器）近端右脚踝。不休息平台上的封堵器，因为通胀/通缩将移动下肢，扰乱超声图像。 </li><li>超声机器设置为B模式。 </li><li>应用超声凝胶的少量动物，近端闭塞箍的下肢。 </li><li>手动对齐附着到立体支架与股静脉，这是通过皮肤可见的超高频线性阵列换能器。股浅动脉应该是可见的&lt;1毫米深。 </li><li>以确认该股浅动脉，而不是股静脉，进行成像，切换至PW-模式。动脉将脉动血流，而不是这将有连续血流相邻静脉。 </li></ol> 4.基线阶段<ol><li>优化B模式图像，类似于如何将在人类15来完成。确保与在两壁可视内膜中层容器的水平，纵向图像观察。通过稍微调整超声探头位置，以确保尽可能多动脉尽可能优化图像是在拍摄窗口中查看。<ol><li>可替代地，调整超声波的设置，通过改变亮度/对比度，聚焦区，频率，动态范围和线密度，以获得更好的图像。还有其他的方法来优化超声图像，但这些详细的说明超出了本协议的范围。 </li></ol></li><li>动脉影像优化后，打开心门控只显示R波期间捕获，以确保只有一个直径收集框架是一个心动周期的每个部分舒张时的图像。 注:心电图门控可在该协议由生理的设置选项下选择ECG门控使用的超声波机器上，但是，此功能可能无法适用于所有超声仪器。图像被优化后的ECG门控应当接通，因为它是难以在较低的帧速率，以获得的图像（即，每R波一次）。没有心电图门控，在大鼠高心脏速率和要求高的帧的组合率捕捉心动周期的舒张部仅允许〜10-20秒的剪辑。数据的每个剪辑繁琐的大小和数量大大增加分析负担。 </li><li>记录使用B模式的基线数据的60秒。 注:超声机总是记录，然而，并非所有的图像被存储在超声机上，因为有上可记录在超声剪辑帧的数目的上限。剪取物长度（即帧数）可在设置调整。建议以每夹帧的最大数量设置。当记录在剪辑的结束（即帧的最大数量达到），录制继续，但剪辑向前滚动捕捉最新的帧。在这种情况下，被抓获的最大帧的限制之外较早帧随后被删除。虽然这些错综复杂在记录机之间不同，记录长度的调整可能是必要的。 </li><li> SWITCH为PW-模式。将光标放置在管腔的中间。样品闸门会自动在参照光标放置，但应可以调整为使用超声键盘宽度。保持≤60°的角度声波作用。 <ol><li>通过改变多普勒波束角度，调整角度声波作用。通过使用超声键盘进行细微调整的角度。如果这两个提供适合于测量的角度，手动通过倾斜动脉到一个更加最佳角度调整超声波探头。如果执行了超声角的任何调整，夺回B模式图像。 </li></ol></li><li>记录速度数据10秒钟。 </li></ol> 5.遮挡阶段<ol><li>膨胀用空气填充10毫升注射器血管阻塞。为了保持空气压力恒定在血管封堵器，折上本身的管放置一个长尾夹在折叠管。 </li><li>切换到PW-模式确认袖口闭塞，就是明证大量减少血流速度。 </li><li>切换到B模式和记录数据，60秒的短片，直到闭塞4:45分钟。 </li><li>切换到PW-模式。保持心脏率的记录，并分析各超声剪辑的时间。 </li></ol> 6.充血阶段<ol><li>松开袖带通过从折叠管长尾夹PW-模式记录时间。录制5秒钟之前和袖口释放后5秒。 </li><li>切换到B模式和记录数据，60秒的短片，直到闭塞后3分钟。保持心脏率的记录，并分析各超声剪辑的时间。 </li><li>口蹄疫完成后请从体检表中的动物和监视，直到它已经恢复了足够的意识，以保持胸骨斜卧。 </li></ol> 7.分析<ol><li>为了分析，出口超声如DICOM文件到装有边缘检测软件的脱机计算机，其允许无偏阻止动脉直径在每个帧的mination。分析是可能的超声机上，但是，它不推荐的，因为它是非常耗费时间和受研究者偏压。 </li><li>期间基线和闭塞相分析60第二区段动脉直径数据，并在过程中充血性相10第二区段。 </li><li>分析使用自动边缘检测软件的流量分析功能血液速度数据。通过在基线和闭塞阶段测量外观均匀的连续5个或多个波形确定平均血流速度。确定袖口释放后立即血流速度反应性充血时的平均血流速度。最高血流速度波形被认为是峰值血流速度。 </li></ol>

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在本研究中，FMD的一种非侵入性测量表现在肱动脉和大鼠股浅动脉。类似于人类6，以下5分钟闭塞期内，在血流速度（即，反应性充血），从而在动脉壁上导致动脉的后续血管舒张增加的剪切速率迅速增加。口蹄疫是在肱动脉和股浅动脉两个观察。此外，还有在FMD动脉之间有很强的关系。虽然最高剪切速率在股浅动脉较高，口蹄疫归到最高剪切速率保持动脉之间牢固的关系。总之，这些结...

血管内皮是蜂窝单层该线条动脉的内腔并且是血管功能的重要调节剂。有从内皮释放众多分子导致血管直径的调制。在这些分子，一氧化氮（NO），似乎是在响应于刺激从血管内皮释放的主血管舒张分子（例如，胰岛素，乙酰胆碱，或剪切应力的变化）1。在血管内皮细胞，编号是由酶产生内皮NO合酶（eNOS）和随后从血管内皮细胞2释放。否扩散到血管平滑肌，其中它引起松弛和增加的血管直径3。 内皮功能障碍可以在利用血流介导的舒张（FMD）技术4,5-人类非侵入性进行评估。口蹄疫已经提出来表示一个功能生物测定内皮衍生在人类中NO的生物利用度，且通常评估在下列一〜5分钟肢闭塞6响应于反应性充血肱或股浅动脉。反应性充血增加了被转导至内皮细胞的7层的剪切力，信令NO 8的释放。虽然近年来，血管舒张由NO释放发起的比重一直争论不休9,10，口蹄疫表明内皮依赖性扩张，并一直被证明预测心血管事件11-13。 迄今为止，成千上万的研究已经使用的口蹄疫技术用于人类血管内皮功能的非侵入性测量。考虑到在重点转化研究近期的转变，对口蹄疫的啮齿类动物的非侵入性测量准则将是非常有价值的。与平移方法保持一致，该协议是建立在肱动脉和苏佩FMD的测量大鼠rficial股动脉，由于这些网站都是人类最常用的测量。在大鼠一个强大的和可重复的口蹄疫响应这个协议的结果，然而，在大鼠口蹄疫测量技术要求高，可能是困难的其他研究者没有视频演示复制。因此，下面的文章将演示口蹄疫肱和大鼠股浅动脉血管无创测量的方法。

<table><tbody><tr><td>Vevo 2100 High Resolution Micro-Ultrasound Imaging System</td><td>VisualSonics, Toronto, ON, CAN</td><td></td><td></td></tr><tr><td>MicroScan Ultra-High Frequency Linear Array Transducer - MS-700 30-70 MHz</td><td>VisualSonics, Toronto, ON, CAN</td><td></td><td></td></tr><tr><td>Vevo Imaging Station</td><td>VisualSonics, Toronto, ON, CAN</td><td></td><td></td></tr><tr><td>Thermasonic gel warmer</td><td>Parker Laboratories, Fairfield, NJ, USA</td><td>82-03</td><td>Optional</td></tr><tr><td>Signacreme electrode cream</td><td>Parker Laboratories, Fairfield, NJ, USA</td><td>17-05</td><td></td></tr><tr><td>Transpore surgical tape</td><td>3M, Maplewood, MN, USA</td><td>1527-1</td><td></td></tr><tr><td>Depilatory cream (&lt;i&gt;e.g.&lt;/i&gt;, Nair)</td><td>General supply</td><td></td><td></td></tr><tr><td>Cotton swabs</td><td>General supply</td><td></td><td></td></tr><tr><td>Ultrasound gel</td><td>General supply</td><td></td><td></td></tr><tr><td>Standard vascular occluder, 10 mm lumen diameter</td><td>Harvard Apparatus, Holliston, MA, USA</td><td>62-0115</td><td></td></tr><tr><td>10 ml syringe with Luer-Lok tip</td><td>General Supply</td><td></td><td>Used for occlusion cuff apparatus</td></tr><tr><td>Paperclip</td><td>General Supply</td><td></td><td>Used for occlusion cuff apparatus</td></tr><tr><td>Hypodermic needle &amp;ndash; 18 gauge&amp;nbsp;</td><td>General Supply</td><td></td><td>Used for occlusion cuff apparatus</td></tr><tr><td>Medium binder clip</td><td>General Supply</td><td></td><td>Used for occlusion cuff apparatus</td></tr></tbody></table>

ultrasound assessment of flow-mediated dilation of the brachial and superficial femoral arteries in rats

Arterial vasodilation to increases in wall shear rate is indicative of vascular endothelial function. In humans, the non-invasive measurement of endothelial function can be achieved by employing the flow-mediated dilation technique, typically performed in the brachial or superficial femoral artery. Briefly, a blood pressure cuff placed distal to an ultrasound probe is inflated to a suprasystolic pressure, which results in limb ischemia. After 5 min of occlusion the cuff is deflated, resulting in reactive hyperemia and increases in wall shear rate that signal vasodilatory molecules to be released from the endothelium eliciting vasodilation. Despite the thousands of studies performing flow-mediated dilation in humans, surprisingly, no studies have performed this technique non-invasively in living rats. Considering the recent shift in focus to translational research, the establishment of guidelines for non-invasive measurement of flow-mediated dilation in rats and other rodents would be extremely valuable. In the following article, a protocol is presented for the non-invasive measurement of flow-mediated dilation in brachial and superficial femoral arteries of rats, as those sites are most commonly measured in humans.

于8 Wistar大鼠的肱动脉和股浅动脉进行血流介导的扩张。的大鼠的定位，如图1所示。 股浅动脉的代表超声图像示于图2。 <img alt="图1" src="/files/ftp_upload/54762/54762fig1.jpg" /> 图1. 鼠和超声定位。 大鼠的定位臂丛（A）的测量和?...

Watch this Scientific Journal Video about Ultrasound Assessment of Flow-Mediated Dilation of the Brachial and Superficial Femoral Arteries in Rats at JoVE.com

Ultrasound Assessment of Flow-Mediated Dilation of the Brachial and Superficial Femoral Arteries in Rats

在人类血管内皮功能的非侵入性的评估可以通过血流介导的扩张的技术来确定。虽然千研究中使用了该技术，没有研究在大鼠进行这种技术非侵入。下面的文章介绍肱血流介导的扩张和大鼠股浅动脉无创测量。

肱血流介导的扩张和大鼠股浅动脉超声评估

Arterial vasodilation to increases in wall shear rate is indicative of vascular endothelial function. In humans, the non-invasive measurement of ...

ultrasound-assessment-flow-mediated-dilation-brachial-superficial

Research

JoVE Journal

Medicine

11.6K 次观看.  University of Utah. 在人类血管内皮功能的非侵入性的评估可以通过血流介导的扩张的技术来确定。虽然千研究中使用了该技术，没有研究在大鼠进行这种技术非侵入。下面的文章介绍肱血流介导的扩张和大鼠股浅动脉无创测量。 

视频: Ultrasound Assessment of Flow-Mediated Dilation of the Brachial and Superficial Femoral Arteries in Rats

Assessment of Vascular Function in Patients With Chronic Kidney Disease

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this is only partially explained by traditional CVD risk factors. Vascular dysfunction is an important non-traditional risk factor, characterized by vascular endothelial dysfunction (most commonly assessed as impaired endothelium-dependent dilation [EDD]) and stiffening of the large elastic arteries. While various techniques exist to assess EDD and large elastic artery stiffness, the most commonly used are brachial artery flow-mediated dilation (FMDBA) and aortic pulse-wave velocity (aPWV), respectively. Both of these noninvasive measures of vascular dysfunction are independent predictors of future cardiovascular events in patients with and without kidney disease. Patients with CKD demonstrate both impaired FMDBA, and increased aPWV. While the exact mechanisms by which vascular dysfunction develops in CKD are incompletely understood, increased oxidative stress and a subsequent reduction in nitric oxide (NO) bioavailability are important contributors. Cellular changes in oxidative stress can be assessed by collecting vascular endothelial cells from the antecubital vein and measuring protein expression of markers of oxidative stress using immunofluorescence. We provide here a discussion of these methods to measure FMDBA, aPWV, and vascular endothelial cell protein expression.

The degree of vascular dysfunction and contributing physiological mechanisms can be assessed in patients with chronic kidney disease by measuring brachial artery flow-mediated dilation, aortic pulse-wave velocity, and vascular endothelial cell protein expression.

血管功能在慢性肾脏疾病的评估

Patients with chronic kidney disease (CKD) have significantly increased risk of cardiovascular disease (CVD) compared to the general population, and this ...

科研

医学

Ultrasound Assessment of Endothelial-Dependent Flow-Mediated Vasodilation of the Brachial Artery in Clinical Research

The vascular endothelium is a monolayer of cells that cover the interior of blood vessels and provide both structural and functional roles. The endothelium acts as a barrier, preventing leukocyte adhesion and aggregation, as well as controlling permeability to plasma components. Functionally, the endothelium affects vessel tone.
Endothelial dysfunction is an imbalance between the chemical species which regulate vessel tone, thombroresistance, cellular proliferation and mitosis. It is the first step in atherosclerosis and is associated with coronary artery disease, peripheral artery disease, heart failure, hypertension, and hyperlipidemia.
The first demonstration of endothelial dysfunction involved direct infusion of acetylcholine and quantitative coronary angiography. Acetylcholine binds to muscarinic receptors on the endothelial cell surface, leading to an increase of intracellular calcium and increased nitric oxide (NO) production. In subjects with an intact endothelium, vasodilation was observed while subjects with endothelial damage experienced paradoxical vasoconstriction.
There exists a non-invasive, in vivo method for measuring endothelial function in peripheral arteries using high-resolution B-mode ultrasound. The endothelial function of peripheral arteries is closely related to coronary artery function. This technique measures the percent diameter change in the brachial artery during a period of reactive hyperemia following limb ischemia.
This technique, known as endothelium-dependent, flow-mediated vasodilation (FMD) has value in clinical research settings. However, a number of physiological and technical issues can affect the accuracy of the results and appropriate guidelines for the technique have been published. Despite the guidelines, FMD remains heavily operator dependent and presents a steep learning curve. This article presents a standardized method for measuring FMD in the brachial artery on the upper arm and offers suggestions to reduce intra-operator variability.

Endothelial dysfunction is associated with numerous disease states and is predictive of adverse cardiovascular events in humans. Flow-mediated vasodilation (FMD) is a non-invasive ultrasound method of evaluating endothelial function. Methodological choices and operator experience may affect results. A systematic approach to FMD in human studies is discussed here.

肱动脉的临床研究超声评价血管内皮依赖性血流介导的血管舒张功能

The vascular endothelium is a monolayer of cells that cover the interior of blood vessels and provide both structural and functional roles. The ...

Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound

We present a protocol for measuring in vivo aortic stiffness in mice using high-resolution ultrasound imaging. Aortic diameter is measured by ultrasound and aortic blood pressure is measured invasively with a solid-state pressure catheter. Blood pressure is raised then lowered incrementally by intravenous infusion of vasoactive drugs phenylephrine and sodium nitroprusside. Aortic diameter is measured for each pressure step to characterize the pressure-diameter relationship of the ascending aorta. Stiffness indices derived from the pressure-diameter relationship can be calculated from the data collected. Calculation of arterial compliance is described in this protocol.
This technique can be used to investigate mechanisms underlying increased aortic stiffness associated with cardiovascular disease and aging. The technique produces a physiologically relevant measure of stiffness compared to ex vivo approaches because physiological influences on aortic stiffness are incorporated in the measurement. The primary limitation of this technique is the measurement error introduced from the movement of the aorta during the cardiac cycle. This motion can be compensated by adjusting the location of the probe with the aortic movement as well as making multiple measurements of the aortic pressure-diameter relationship and expanding the experimental group size.

Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound

We describe a technique for measuring aortic stiffness from its pressure-diameter relationship in vivo in mice. Aortic diameter is recorded by ultrasound and aortic pressure is measured invasively with a solid-state pressure catheter. Blood pressure is changed incrementally and the resulting diameter is measured.

测量升主动脉刚度<em&gt;在体内</em&gt;小鼠使用超声

We present a protocol for measuring in vivo aortic stiffness in mice using high-resolution ultrasound imaging. Aortic diameter is measured by ultrasound ...

A Methodological Approach to Non-invasive Assessments of Vascular Function and Morphology

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis. Damage to the endothelium may predispose the vessel to atherosclerosis and increase the risk for cardiovascular disease. Assessments of peripheral endothelial function are good indicators of early abnormalities in the vascular wall and correlate well with assessments of coronary endothelial function. The present manuscript details the important methodological steps necessary for the assessment of microvascular endothelial function using laser Doppler imaging with iontophoresis, large vessel endothelial function using flow-mediated dilatation, and carotid atherosclerosis using carotid artery ultrasound. A discussion on the methodological considerations for each of the techniques is also presented, and recommendations are made for future research.

The present article describes the methodological considerations for several non-invasive assessments of vascular function and morphology that are commonly used in medical research to assess different stages of atherosclerosis.

方法论方法血管功能和形态的非侵入性评估

The endothelium is the innermost lining of the vasculature and is involved in the maintenance of vascular homeostasis.  Damage to the endothelium may ...

Ultrasound Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow reserve (CFR) in humans. Reduced CFR is accompanied by marked intramyocardial and pericoronary fibrosis and is used as an indication of the severity of dysfunction. This study explores, step-by-step, the real-time changes measured in the coronary flow velocity, CFR and systolic to diastolic peak velocity (S/D) ratio in the setting of an aortic banding model in mice. By using a Doppler transthoracic imaging technique that yields reproducible and reliable data, the method assesses changes in flow in the septal coronary artery (SCA), for a period of over two weeks in mice, that previously either underwent aortic banding or thoracotomy. 
During imaging, hyperemia in all mice was induced by isoflurane, an anesthetic that increased coronary flow velocity when compared with resting flow. All images were acquired by a single imager. Two ratios, (1) CFR, the ratio between hyperemic and baseline flow velocities, and (2) systolic (S) to diastolic (D) flow were determined, using a proprietary software and by two independent observers. Importantly, the observed changes in coronary flow preceded LV dysfunction as evidenced by normal LV mass and fractional shortening (FS). 
The method was benchmarked against the current gold standard of coronary assessment, histopathology. The latter technique showed clear pathologic changes in the coronary artery in the form of peri-coronary fibrosis that correlated to the flow changes as assessed by echocardiography. 
The study underscores the value of using a non-invasive technique to monitor coronary circulation in mouse hearts. The method minimizes redundant use of research animals and demonstrates that advanced ultrasound-based indices, such as CFR and S/D ratios, can serve as viable diagnostic tools in a variety of investigational protocols including drug studies and the study of genetically modified strains.

Coronary flow reserve (CFR) is useful for assessment of myocardial oxygen demand and evaluation of cardiovascular risk. This study establishes a step-by-step transthoracic Doppler echocardiographic (TTDE) method for longitudinal monitoring of the changes in CFR, as measured from coronary artery in mice, under the experimental pressure overload of aortic banding.

冠脉流量和冠状动脉血流储备用小鼠压力超负荷基于模型的超声评估

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow ...

Ultrasound Assessment of Endothelial Function: A Technical Guideline of the Flow-mediated Dilation Test

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a pathological condition characterized mainly by a disruption in the balance between vasodilator and vasoconstrictor substances and is proposed to play an important role in the development of atherosclerotic cardiovascular disease. Therefore, a precise evaluation of endothelial function in humans represents an important tool that could help better understand the etiology of multiple cardio-centric pathologies.
Over the past twenty-five years, many methodological approaches have been developed to provide an assessment of endothelial function in humans. Introduced in 1989, the FMD test incorporates a forearm occlusion and subsequent reactive hyperemia that promotes nitric oxide production and vasodilation of the brachial artery. The FMD test is now the most widely utilized, non-invasive, ultrasonic assessment of endothelial function in humans and has been associated with future cardiovascular events.
Although the FMD test could have clinical utility, it is a physiological assessment that has inherited several confounding factors that need to be considered. This article describes a standardized protocol for determining FMD including the recommended methodology to help minimize the physiological and technical issues and improve the precision and reproducibility of the assessment.

The flow mediated dilation (FMD) test is the most commonly utilized, non-invasive, ultrasound assessment of endothelial function in humans. Although the FMD test has been related with the prediction of future cardiovascular disease and events, it is a physiological assessment with many inherent confounding factors that need to be considered.

血管内皮功能的超声评估:血流介导的舒张试验的技术指导原则

Cardiovascular disease is the primary cause of mortality and a major cause of disability worldwide. The dysfunction of the vascular endothelium is a ...

Ultrasound-based Pulse Wave Velocity Evaluation in Mice

Arterial stiffness can be evaluated by calculating pulse wave velocity (PWV), i.e., the speed with which the pulse wave travels in a conduit vessel. This parameter is being increasingly investigated in small rodent models in which it is used for assessing alterations in vascular function related to particular genotypes/treatments or for characterizing cardiovascular disease progression. This protocol describes an image processing algorithm which leads to non-invasive arterial PWV measurement in mice using ultrasound (US) images only. The proposed technique has been used to assess abdominal aorta PWV in mice and evaluate its age-associated changes.
Abdominal aorta US scans are obtained from mice under gaseous anesthesia using a specific US device equipped with high-frequency US probes. B-mode and Pulse-Wave Doppler (PW-Doppler) images are analyzed in order to obtain diameter and mean velocity instantaneous values, respectively. For this purpose, edge detection and contour tracking techniques are employed. The single-beat mean diameter and velocity waveforms are time aligned and combined in order to achieve the diameter-velocity (lnD-V) loop. PWV values are obtained from the slope of the linear part of the loop, which corresponds to the early systolic phase.
With the present approach, anatomical and functional information about the mouse abdominal aorta can be non-invasively achieved. Requiring the processing of US images only, it may represent a useful tool for the non-invasive characterization of different arterial sites in the mouse in terms of elastic properties. The application of the present technique can be easily extended to other vascular districts, such as the carotid artery, thus providing the possibility to obtain a multi-site arterial stiffness assessment.

Arterial stiffness represents a key factor in cardiovascular disease and pulse wave velocity (PWV) can be considered as a surrogate index for arterial stiffness. This protocol describes an image processing algorithm for calculating PWV in mice based on ultrasound image processing that is applicable at different arterial sites.

基于超声脉搏波速度评价小鼠

Arterial stiffness can be evaluated by calculating pulse wave velocity (PWV), i.e., the speed with which the pulse wave travels in a conduit vessel. This ...

Evaluation of Vascular Control Mechanisms Utilizing Video Microscopy of Isolated Resistance Arteries of Rats

This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other vessels), and describes techniques for evaluating tissue perfusion using Laser Doppler Flowmetry (LDF) and microvessel density utilizing fluorescently labeled Griffonia simplicifolia (GS1) lectin. Current methods for studying isolated resistance arteries at transmural pressures encountered in vivo and in the absence of parenchymal cell influences provide a critical link between in vivo studies and information gained from molecular reductionist approaches that provide limited insight into integrative responses at the whole animal level. LDF and techniques to selectively identify arterioles and capillaries with fluorescently-labeled GS1 lectin provide practical solutions to enable investigators to extend the knowledge gained from studies of isolated resistance arteries. This paper describes the application of these techniques to gain fundamental knowledge of vascular physiology and pathology in the rat as a general experimental model, and in a variety of specialized genetically engineered &#34;designer&#34; rat strains that can provide important insight into the influence of specific genes on important vascular phenotypes. Utilizing these valuable experimental approaches in rat strains developed by selective breeding strategies and new technologies for producing gene knockout models in the rat, will expand the rigor of scientific premises developed in knockout mouse models and extend that knowledge to a more relevant animal model, with a well understood physiological background and suitability for physiological studies because of its larger size.

This manuscript describes in vitro video microscopy protocols for evaluating vascular function in rat cerebral resistance arteries. The manuscript also describes techniques for evaluating microvessel density with fluorescently labeled lectin and tissue perfusion using Laser Doppler Flowmetry.

利用大鼠离体阻力动脉的视频显微镜对血管控制机制的评价

This protocol describes the use of in vitro television microscopy to evaluate vascular function in isolated cerebral resistance arteries (and other ...

Measurement of Pulse Propagation Velocity, Distensibility and Strain in an Abdominal Aortic Aneurysm Mouse Model

An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the abdominal aorta that exceeds the maximal intraluminal diameter (MILD) by 1.5 times of its original size. Clinical and experimental studies have shown that small aneurysms may rupture, while a subpopulation of large aneurysms may remain stable. Thus, in addition to the measurement of intraluminal diameter of the aorta, knowledge of structural traits of the vessel wall may provide important information to assess the stability of the AAA. Aortic stiffening has recently emerged as a reliable tool to determine early changes in the vascular wall. Pulse propagation velocity (PPV) along with the distensibility and radial strain are highly useful ultrasound-based methods relevant for assessing aortic stiffness. The primary purpose of this protocol is to provide a comprehensive technique for the use of ultrasound imaging system to acquire images and analyze the structural and functional properties of the aorta as determined by MILD, PPV, distensibility and radial strain.

This manuscript describes a detailed protocol for using high frequency ultrasound imaging to measure luminal diameter, pulse propagation velocity, distensibility and radial strain on a mouse model of abdominal aortic aneurysm.

腹部主动脉瘤小鼠模型中脉冲传播速度、失散性和应变的测量

An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the abdominal aorta that exceeds the maximal intraluminal diameter (MILD) by 1.5 ...

免疫与感染

<meta charset="utf8"></head><body>使用动脉硬度和内皮功能进行心血管评估

Pulse-Wave Velocity, Flow-Mediated Dilation, and Carotid Intima-Media Thickness to Assess Cardiovascular Risk in Population with Metabolic Syndrome

Pulse-wave velocity (PWV), flow-mediated dilation (FMD), and carotid intima-media thickness (CIMT) are established methods used in research and clinical settings to assess arterial stiffness, endothelial function, and subclinical atherogenesis. These measurements may reflect vascular disease and atherosclerotic progression, which are major causes of adverse cardiovascular events. These methods are particularly valuable in determining cardiovascular dysfunction among populations with different risk factors, such as diabetes mellitus, hypertension, and other metabolic dysfunction-related conditions. They provide a non-invasive and reliable source of information that complements clinical practice. Early detection, risk assessment, and therapeutic decisions regarding cardiovascular disease can be achieved, ultimately contributing to improved patient outcomes. Traditional tools for evaluating cardiovascular disease do not reveal whether metabolic syndrome affects early subclinical cardiovascular disease in patients with obesity. Recent research has highlighted the importance of including arterial stiffness and endothelial function in a comprehensive cardiovascular assessment. Therefore, the aim of the present study is to describe methods that provide information on early subclinical vascular aging, endothelial dysfunction, and atherogenic disease, enabling vascular-targeted risk stratification among populations with obesity and different metabolic profiles.

<meta charset="utf8"></head><body>作者聚焦：评估代谢综合征患者的心血管特征

Endothelial/vascular aging and atherogenesis are key mechanisms that promote the development of cardiovascular diseases. The present protocol describes methods to evaluate arterial stiffness, endothelial dysfunction, and atherogenesis in patients with related risk factors, which are highly valuable in the cardiovascular research field.

脉搏波速度、血流介导的扩张和颈动脉内膜中层厚度评估代谢综合征人群的心血管风险

Pulse-wave velocity (PWV), flow-mediated dilation (FMD), and carotid intima-media thickness (CIMT) are established methods used in research and clinical ...