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
Summary
此协议的目的是通过横向主动脉缩窄创建心脏疾病的小鼠模型评估无创心脏结构和功能改变，采用B和M型超声心动图和彩色/脉冲多普勒成像。
Abstract
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.
Introduction
Mouse models of heart disease, such as TAC and myocardial infarction (MI), have been proven to be valuable to study disease mechanisms as well as to develop novel therapeutic strategies3. TAC initially induces compensatory hypertrophy, but prolonged pressure overload leads to cardiac dilatation and heart failure4. The tightness of the aortic constriction directly determines the degree of cardiac hypertrophy and its transition to heart failure. Noninvasive and reliable measurement of pressure gradient across the aortic constriction is essential for the success of these studies. Doppler imaging has been used to assess pressure gradient produced by TAC5, which is a noninvasive alternative for catheter-based pressure measurement.
Echocardiography has been widely used to noninvasively measure cardiac morphology as well as systolic and diastolic function in mice6-8. Two-dimensional B-mode imaging is used to detect abnormal movements or structural changes of the heart. One-dimensional M-mode imaging is used for quantification of cardiac dimensions and contractility. Color and PW Doppler imaging has recently been used on rodent ultrasound, which has broad applications for echocardiography, including measurement of flow directionality and velocity, as well as systolic and diastolic performance9.
Longitudinal real-time monitoring of cardiac function using echocardiography in B-mode, M-mode, color and PW Doppler mode provides comprehensive assessment of cardiac structure and function in mice under physiological and pathological conditions. Here we provide a detailed description of the use of echocardiographic imaging to monitor dynamic cardiac morphological and functional changes in mice following TAC or sham surgery.
Protocol
Representative Results
Discussion
超声心动图已被广泛用于评估心脏疾病2,6的啮齿动物模型的心脏功能。相比于侵入或终端的方法，如压力容积环测量11和体外工作心脏12，超声心动图提供了强大的，非侵入性工具来评估在动物活体心脏正在进行结构和功能的改变。获得可靠的数据，通过仔细调节加热装置和麻醉水平保持体温和心脏速率生理范围13内是很重要的。所有图像应该始终根据标准?…
Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors have nothing to disclose.
Materials
| Anesthesia equipment | Harvard Apparatus, 84 October Hill Road Holliston, MA |
723015 | |
| Vevo 2100 Imaging System | VisualSonics Inc., 3080 Yonge Street Suite 6100, Box 66, Toronto, Ontario, Canada | Vevo 2100 | |
| Aquasonic ultrasound gel | Parker Laboratories, 286 Eldridge Rd, Fairfield, NJ | 03-50 | |
| Isoflurane | Piramal Healthcare, Inc, 3950 Schelden Circle Bethlehem, PA |
NDC 66794-017-25 | |
| F/air anesthesia gas filter unit | A.M. Bickford, Inc, 12318 Big Tree Rd, Wales Center, NY | 80120 |
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