右心小鼠的超声心动图评价
Summary
本文提供了一个协议，右心室的大小和小鼠肺动脉高压的超声心动图评价。应用范围包括表型测定和序列评估转基因和心肌病和肺血管病变的毒素诱导的小鼠模型。
Abstract
转基因和肺动脉高压（PAH）的毒性模型被广泛用于研究PAH的病理生理和调查潜在的治疗方法。定的费用和参与创建疾病的动物模型的时候，也有研究工具，以准确地评估疾病的表型的表达是至关重要的。右心室功能不全是肺动脉高压的主要表现。超声心动图是在啮齿动物模型右心室功能的无创性评估的主体，有明确的翻译给人类在其中相同的工具用于的优势。肺动脉高压小鼠模型发布超声心动图协议所缺乏的。
在这篇文章中，我们描述了一个协议，用于评估RV和肺动脉高压的小鼠模型具有显性负突变BMPRII肺血管的功能，但是，这个协议适用于影响肺血管或心脏右任何疾病。我们提供动物制剂，图像采集和血液动力学计算每搏量，心输出量和肺动脉压力的估计值的详细说明。
Introduction
升高的肺动脉压和右心室（RV）功能障碍是肺血管疾病的动物模型和人类患者的肺动脉高压（PAH）的标志。 PAH的转基因和毒性（ 如野百合碱或缺氧）模型被广泛用于研究PAH的病理生理和调查潜在的治疗方法。定的费用和参与创建疾病的动物模型的时候，也有研究工具，以准确地评估疾病的表型的表达是至关重要的。
超声心动图是在啮齿类动物模型1,2心室功能的无创性评估的中流砥柱。超声心动图具有明显的翻译给人类在其中相同的工具用于的优势。此外，一些遗传模型表现出不完全外显3，无创识别受影响的动物的能力，节省了宝贵的时间和资源。 disea的无创性评估在不牺牲动物本身的严重程度也可以让研究人员连续调查研究治疗的效果。这一点尤其重要，因为快速性与平移疗法可进展为人体试验4,5。
在人类中，房车大小和肺动脉高压的超声心动图评价是由于胸骨位置和房车6的不规则形状特别具有挑战性。啮齿类动物模型具有体积小的附加挑战和极其快速的心脏速率（300〜700次/ min）。最近的进展包括更高的帧速率和更小的换能器具有改进的图像质量，在某些实验方案甚至允许有意识的成像，虽然大多数啮齿动物成像在麻醉下7,8完成。超声心动图在肺动脉高压大鼠模型的极好的实验方案进行了描述和验证对MRI和侵入血流动力学1,9。然而，超声心动图发布肺动脉高压小鼠模型的协议所缺乏的。
在这篇文章中，我们描述了一个协议，用于评估PAH的小鼠模型具有显性负突变BMPRII和肺动脉环缩后孤立右室后负荷模型房车和肺血管的功能，但是，这个协议适用于任何疾病的影响肺血管或心脏的权利。我们将介绍动物准备和房车的尺寸和功能以及主肺动脉（PA）的大小的详细的评估。我们还演示了估计每搏输出量和心输出量所需要的技术和计算。技术上的限制，排除肺动脉压精确的多普勒估计，但我们已经应用了经过验证的人代孕，肺动脉加速时间，估计PA的压力。
Protocol
Representative Results
Discussion
小鼠模型中的疾病，无论是转基因或毒素相关的，需要的表型的验证，该模型实际上是概括了人类疾病它被用于仿真。此验证通常可以通过一个特定特征的存在或不存在来实现，对于肿瘤的例子发展。然而，导致血流动力学异常，如左心室肥厚或我们的转基因PAH的模型主动脉缩窄模型模型更难以验证。这些模型需要血液动力学或工具的任意终端测量到测量无创血流动力学异常和心脏功能。超声心?…
Disclosures
The authors have nothing to disclose.
Materials
| Vevo 770 High Resolution Micro-Ultrasound System | Visualsonics Inc. | get more info at www.visualsonics.com/products | |
| RMV (Real-Time MicroVisualization) 704B 40 mH Scanhead w/ Encapsulated Transducer | Visualsonics Inc. | get more info at www.visualsonics.com/products | |
| Vevo Integrated Rail System including the Physioogical Monitoring System | Visualsonics Inc. | get more info at www.visualsonics.com/products | |
| Computer Monitor set up for use with the Vevo770 | DELL or other General Supplier | ||
| Computer Mouse set up for use with the Vevo770 | General Supplier | ||
| Vevo770 Cardiac Package Software | Visualsonics Inc. | get more info at www.visualsonics.com/products | |
| VetEquip Portable Tabletop Anesthesia Machine with an Isoflurane Vaporizer | VetEquip | get more info at vetequip.com | |
| Activated Charcoal Waste Gas Containers | VetEquip/Vaporguard | 931401 | get more info at vetequip.com |
| Puralube Eye Ointment | Henry Schein | get more info at henryschein.com | |
| Ecogel 100 Ultrasound Gel | EcoMed Pharmaceuticals | 30GB | get more info at ecomed.com |
| 3M Transpore Tape | Fisher Scientific | 1527-0 | get more info at fishersci.com |
| Small Flathead Screwdriver | General Supplier | ||
| Sterile H2O | DDI H2O from faucet and then autoclave | ||
| 6 in Cotton Tipped Applicators | Fisher Scientific | get more info at fishersci.com | |
| Nair (depilatory cream) | General Supplier | ||
| 2 in x 2 in Gauze Sponges | Fisher Scientific | get more info at fishersci.com |
References
- Urboniene, D., Haber, I., Fang, Y. H., Thenappan, T., Archer, S. L. Validation of high-resolution echocardiography and magnetic resonance imaging vs. high-fidelity catheterization in experimental pulmonary hypertension. Am. J. Physiol. Lung Cell Mol. Physiol. 299, 401-412 (2010).
- Rottman, J. N., Ni, G., Brown, M. Echocardiographic evaluation of ventricular function in mice. Echocardiography. 24, 83-89 (2007).
- West, J., et al. Pulmonary hypertension in transgenic mice expressing a dominant-negative BMPRII gene in smooth muscle. Circ. Res. 94, 1109-1114 (2004).
- Ghofrani, H. A., Seeger, W., Grimminger, F. Imatinib for the treatment of pulmonary arterial hypertension. N. Engl. J. Med. 353, 1412-1413 (2005).
- Gomberg-Maitland, M., et al. A dosing/cross-development study of the multikinase inhibitor sorafenib in patients with pulmonary arterial hypertension. Clin. Pharmacol. Ther. 87, 303-310 (2010).
- Brittain, E., et al. Right ventricular plasticity and functional imaging. Pulm. Circ. 2, 309-326 (2012).
- Yang, X. P., et al. Echocardiographic assessment of cardiac function in conscious and anesthetized mice. Am. J. Physiol. 277, 1967-1974 (1999).
- Suehiro, K., et al. Assessment of segmental wall motion abnormalities using contrast two-dimensional echocardiography in awake mice. Am. J. Physiol. Heart Circ Physiol. 280, 1729-1735 (2001).
- Jones, J. E., et al. Serial noninvasive assessment of progressive pulmonary hypertension in a rat model. Am. J. Physiol. Heart Circ. Physiol. 283, 364-371 (2002).
- Devaraj, A., et al. Detection of pulmonary hypertension with multidetector CT and echocardiography alone and in combination. Radiology. 254, 609-616 (2010).
- Kitabatake, A., et al. Noninvasive evaluation of pulmonary hypertension by a pulsed Doppler technique. Circulation. 68, 302-309 (1983).
- Yared, K., et al. Pulmonary artery acceleration time provides an accurate estimate of systolic pulmonary arterial pressure during transthoracic echocardiography. J. Am. Soc. Echocardiogr. 24, 687-692 (2011).
- Cheung, M. C., et al. Body surface area prediction in normal, hypermuscular, and obese mice. J. Surg. Res. 153, 326-331 (2009).
- Patten, R. D., Hall-Porter, M. R. Small animal models of heart failure: development of novel therapies, past and present. Circ. Heart Fail. 2, 138-144 (2009).
- Baumgartner, H., et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice. J. Am. Soc. Echocardiogr. 22, 1-23 (2009).
- Arkles, J. S., et al. Shape of the right ventricular Doppler envelope predicts hemodynamics and right heart function in pulmonary hypertension. Am. J. Respir. Crit. Care Med. 183, 268-276 (2011).
- Wiesmann, F., et al. Analysis of right ventricular function in healthy mice and a murine model of heart failure by in vivo MRI. Am. J. Physiol. Heart Circ. Physiol. 283, 1065-1071 (2002).
- West, J., et al. A potential role for Insulin resistance in experimental pulmonary hypertension. Eur. Respir. J. , (2012).
- Johnson, J. A., et al. Cytoskeletal defects in Bmpr2-associated pulmonary arterial hypertension. Am. J. Physiol. Lung Cell Mol. Physiol. 302, L474-L484 (2012).
- Johnson, J. A., West, J., Maynard, K. B., Hemnes, A. R. ACE2 improves right ventricular function in a pressure overload model. PLoS One. 6, e20828 (2011).
