作者承认生物技术系，印度政府为这个项目提供财政支持。阿吉特·库马尔GS与科学和工业研究，印度政府和Binil拉吉与医学研究，印度政府的印第安人理事会高级研究奖学金理事会高级研究奖学金得到了支持。

动物实验获得学院动物伦理委员会批准后执行。 Wistar大鼠容纳下一个12小时黑暗的光周期，恒定室温（24±2℃）与食物和水随意（按照CPCSEA准则）。 1）手术前护理和麻醉<ol><li>根据抗生素伞24小时保持大鼠（约200g体重）术前通过口服阿莫西林（剂量：水500毫克/升）。 </li><li>通过在121℃下高压灭菌15分钟进行消毒所有外科工具（如剪刀，镊子，夹子施放器，缝合针和缝合针夹持器）。 </li><li>使用加热垫保持动物的体温约37℃，以避免在心脏速率迅速下降。 </li><li>注意避免之前和期间手术的动物脱水。 </li><li>麻醉中的感应腔的大鼠用3％异氟烷与混合0.5-1.0升/分钟100％的氧气;与1.5％异氟醚维持麻醉。 </li><li>检查踏板反射确认成功麻醉。 </li></ol> 2）准备手术部位<ol><li>保持对大鼠温控加热垫的顶部在仰卧位。 </li><li>定位橡皮筋在老鼠的门牙，以保持动物的位置，同时维持麻醉用鼻锥。 </li><li>从领口取下毛皮，离开了大鼠胸部区域（最好使用电动剃须刀）。 </li><li>消毒手术部位与聚维酮碘溶液，然后用70％的乙醇。 </li><li>使用无菌悬垂到手术过程中只露出手术部位。 注：对于照顾动物一个额外的选项，0.25％布比卡因ID（2.5毫克/千克）可结合在每个切口部位切开局部麻醉/镇痛前。 </li></ol> 3）气管插管鼠<ol><li>使在平行于用无菌手术刀片气管皮肤的小切口，仔细分离下层组织以暴露气管。 </li><li>适用的气管下方4-0丝线缝合线领带和轻轻抬起领带向上。 </li><li>使2软骨环之间的半路上切口并插入气管套管插入大鼠的气管中。 </li><li>气管插管连接到啮齿动物呼吸机维持50次呼吸/分钟，1.70毫升潮气量和0.60秒的吸气时间（对于大鼠用200g体重）的呼吸率。 </li></ol>升主动脉4）缩窄<ol><li>经过感应肋骨的位置用手指，做出对第二和第三肋骨之间左胸壁约2厘米的皮肤切口。 </li><li>通过层分离肋间肌层和做一个切口约1.5厘米长的第二和第三肋之间。 （护理应采取n到避免任何损伤肺，同时使肋之间切口） </li><li>收回肋骨和定位主动脉升部。 </li><li>放置一个小尺寸的钛夹围绕升主动脉带有施加的帮助，从而收缩主动脉到原始直径的50-60％。 </li><li>以下的主动脉缩窄，接近所述第二和第三肋与3.0 prolene线中的间断缝合图案。同时，暂停呼吸约2-4秒，以重新膨胀肺部。 </li><li>放在附近的肌肉层，3.0普理灵缝线和皮肤4.0丝线缝合在间断缝合模式。合成的非吸收缝合线可以用来代替丝的缝合皮肤。 </li><li>从一次自主呼吸重新建立大鼠去除气管套管。 </li><li>关闭气管开口3.0普理灵缝线和皮肤层4.0丝线缝合。 </li><li>让动物恢复对T他通过逐渐降低麻醉和呼吸机辅助呼吸的加热垫。 </li><li>在年龄匹配的假手术对照组动物，进行气管切开及开胸无升主动脉缩窄。 </li></ol> 5）术后护理<ol><li>消毒手术区域用聚维酮碘溶液。 </li><li>由于手术后的镇痛，曲马多注射腹腔内（10毫克/公斤体重/天）1周。 </li><li>注入无菌生理盐水腹腔内，如果脱水体征手术（大约1毫升）后出现。 </li><li>辖阿莫西林口服，混合饮水，七天（剂量：水500毫克/升）。 </li><li>从后下吸入麻醉10天手术的皮肤去除任何剩余的丝线缝合。 </li></ol> 6）确认升主动脉的成功缩窄的<ol><li>执行跨胸二维多普勒超声心动图来确定INTENSITY由升主动脉的收缩所产生的压力超负荷。 </li><li>如前所述麻醉大鼠1周手术后（步骤1.5） </li><li>将超声换能器在上文胸骨位置横跨升主动脉的收缩部记录的压力梯度。 注：大鼠在主动脉狭窄部位约60毫米汞柱的压力梯度会出现严重的心肌肥厚约8-10周后手术。 </li></ol>

<ol>
	<li>Patten, R. D., Hall-Porter, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+animal+models+of+heart+failure:+development+of+novel+therapies,+past+and+present.">Small animal models of heart failure: development of novel therapies, past and present.</a> Circ Heart Fail. 2, 138-144 (2009).</li><li>Weinberg, E. O., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angiotensin-converting+enzyme+inhibition+prolongs+survival+and+modifies+the+transition+to+heart+failure+in+rats+with+pressure+overload+hypertrophy+due+to+ascending+aortic+stenosis.">Angiotensin-converting enzyme inhibition prolongs survival and modifies the transition to heart failure in rats with pressure overload hypertrophy due to ascending aortic stenosis.</a> Circulation. 90, 1410-1422 (1994).</li><li>Schunkert, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+rat+cardiac+angiotensin+converting+enzyme+activity+and+mRNA+expression+in+pressure+overload+left+ventricular+hypertrophy.+Effects+on+coronary+resistance,+contractility,+and+relaxation.">Increased rat cardiac angiotensin converting enzyme activity and mRNA expression in pressure overload left ventricular hypertrophy. Effects on coronary resistance, contractility, and relaxation.</a> J Clin Invest. 86, 1913-1920 (1990).</li><li>Hasenfuss, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+human+cardiovascular+disease,+heart+failure+and+hypertrophy.">Animal models of human cardiovascular disease, heart failure and hypertrophy.</a> Cardiovasc Res. 39, 60-76 (1998).</li><li>Litwin, S. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serial+echocardiographic-Doppler+assessment+of+left+ventricular+geometry+and+function+in+rats+with+pressure-overload+hypertrophy.+Chronic+angiotensin-converting+enzyme+inhibition+attenuates+the+transition+to+heart+failure.">Serial echocardiographic-Doppler assessment of left ventricular geometry and function in rats with pressure-overload hypertrophy. Chronic angiotensin-converting enzyme inhibition attenuates the transition to heart failure.</a> Circulation. 91, 2642-2654 (1995).</li><li>Miyamoto, M. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adenoviral+gene+transfer+of+SERCA2a+improves+left-ventricular+function+in+aortic-banded+rats+in+transition+to+heart+failure.">Adenoviral gene transfer of SERCA2a improves left-ventricular function in aortic-banded rats in transition to heart failure.</a> Proc Natl Acad Sci U S A. 97, 793-798 (2000).</li><li>Kagaya, Y., Hajjar, R. J., Gwathmey, J. K., Barry, W. H., Lorell, B. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+angiotensin-converting+enzyme+inhibition+with+fosinopril+improves+depressed+responsiveness+to+Ca2++in+myocytes+from+aortic-banded+rats.">Long-term angiotensin-converting enzyme inhibition with fosinopril improves depressed responsiveness to Ca2+ in myocytes from aortic-banded rats.</a> Circulation. 94, 2915-2922 (1996).</li><li>Del Monte, F., Butler, K., Boecker, W., Gwathmey, J. K., Hajjar, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+technique+of+aortic+banding+followed+by+gene+transfer+during+hypertrophy+and+heart+failure.">Novel technique of aortic banding followed by gene transfer during hypertrophy and heart failure.</a> Physiol Genomics. 9, 49-56 (2002).</li><li>Turcani, M., Rupp, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+failure+development+in+rats+with+ascending+aortic+constriction+and+angiotensin-converting+enzyme+inhibition.">Heart failure development in rats with ascending aortic constriction and angiotensin-converting enzyme inhibition.</a> Br J Pharmacol. 130, 1671-1677 (2000).</li><li>Kerem, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lung+endothelial+dysfunction+in+congestive+heart+failure:+role+of+impaired+Ca2++signaling+and+cytoskeletal+reorganization.">Lung endothelial dysfunction in congestive heart failure: role of impaired Ca2+ signaling and cytoskeletal reorganization.</a> Circ Res. 106, 1103-1116 (2010).</li><li>Almeida, A. C., van Oort, R. J., Wehrens, X. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transverse+aortic+constriction+in+mice.">Transverse aortic constriction in mice.</a> J Vis Exp. (38), (2010).</li></ol>

作者什么都没有透露。

有几种手术的型号为感应压力超负荷以及心肌肥厚和心脏衰竭。在小动物，Lorell和他的同事开发了我们在这里所描述的模型，他们报告的代偿性心肌肥厚后8周主动脉缩窄5的发生。心脏的变化逐渐进展到失代偿状态，然后导致心脏衰竭。这种模式的主要优点是逐步发病增加，左心室压力，从而类似于在慢性高血压的临床情况的。它也是一种合适的动物模型用于研究相关 ​​的左心脏衰竭?...

小动物模型是用于在心脏肥大及其进展为心脏衰竭的发展慢性变化的研究最优选的工具。通过手术方法心脏衰竭模型最初是在大鼠为这些动物都是敞胸外科手术，超声心动图血流动力学参数和评估最合适。它们还提供了充足的验尸样本进行组织，细胞和分子水平的研究1。升主动脉缩窄是最常见的和成功的手术模型用于创建压力超负荷心脏衰竭2，3中的一个。这种模式是非常适合从肥大心脏衰竭4在过渡期间，研究细胞和亚细胞重塑事件和心脏的收缩性能。 这种模式的主要优点是逐渐发生的5心脏压力超负荷，&lt;/燮&gt; 6。这种模式是因为其缓慢但稳定的进展从补偿心肌肥厚到失代偿阶段，最后到心脏衰竭阶段临床相关性。持续时间为心肌肥厚心脏衰竭和相关生理变化的进程主要受狭窄程度产生7。升主动脉缩窄可以通过两种方式来进行，或者通过使用缝合线或者由应用的金属夹子8,9。使用金​​属夹，用于主动脉缩窄的主要优点是，外科手术是不太复杂的。在该方法中人们必须找出同上瓣膜升主动脉，插入片段围绕主动脉取得缩颈的期望的水平。胸部牵开器是没有必要在此过程。主动脉缩窄通过缝合需要更多的手术操作用于放置针头升主动脉旁，周围缝合到产生主动脉缩窄的所需的水平。后者的技术是更多的时间时，与使用金属夹子对主动脉缩窄比较耗时。在这个视频中描述的方法演示了外科手术升大鼠主动脉缩窄，使压力超负荷创造左心室肥厚模型。

<table border="0" cellpadding="0" cellspacing="0" width="742">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Wistar rats</td>
			<td style="width:149px;"></td>
			<td style="width:119px;"></td>
			<td style="width:220px;">Maintained at ARF, RGCB</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Inhalation anaesthesia systems&#160;</td>
			<td style="width:149px;">VetEquip</td>
			<td style="width:119px;">AB19276</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Rodent ventilator</td>
			<td style="width:149px;">CWE Inc</td>
			<td style="width:119px;">SAR- 830/AP&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Rat tracheal cannula</td>
			<td style="width:149px;">CWE Inc</td>
			<td style="width:119px;">13-21032</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Ultrasound system</td>
			<td style="width:149px;">Philips</td>
			<td style="width:119px;">HD7</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Ultrasound transducer</td>
			<td style="width:149px;">Philips</td>
			<td style="width:119px;">S 12</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Titanium clip (small)</td>
			<td style="width:149px;">Horizon</td>
			<td style="width:119px;">1204</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Clip applicator</td>
			<td style="width:149px;">Weck</td>
			<td style="width:119px;">137081</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Electric shaver</td>
			<td style="width:149px;">Vinverth</td>
			<td style="width:119px;">VBT0817</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">BP blade (size:11)</td>
			<td style="width:149px;">Surgeon</td>
			<td style="width:119px;">REF10111</td>
			<td>Preparation of surgical site</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Tramadol</td>
			<td style="width:149px;">Orchid health care</td>
			<td style="width:119px;">OCH043</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Amoxycillin Hydrochloride</td>
			<td style="width:149px;">Ranbaxy</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Isoflurane</td>
			<td style="width:149px;">Piramal health care</td>
			<td style="width:119px;">A23M10A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Syringes</td>
			<td style="width:149px;">BD</td>
			<td style="width:119px;">2015-09</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">4-0 braided silk</td>
			<td style="width:149px;">Diamond</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">3-0 prolene</td>
			<td style="width:149px;">Johnson&#38;Johnson</td>
			<td style="width:119px;">NW018</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Surgical tape</td>
			<td style="width:149px;">Romsons</td>
			<td style="width:119px;">SH 6301</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Povidone iodine</td>
			<td style="width:149px;">Win Medicare</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:255px;">Temp. controlled heating pad</td>
			<td style="width:149px;">Flamingo</td>
			<td style="width:119px;">HC1003</td>
			<td></td>
		</tr>
	</tbody>
</table>

ascending aortic constriction in rats for creation of pressure overload cardiac hypertrophy model

升主动脉缩窄是一个用于创建诱导的心肌肥厚和心脏衰竭压力超负荷最常见和最成功的手术模型。在这里，我们描述了使用一个小的金属夹子由升主动脉缩窄建立压力负荷和心肌肥厚大鼠详细的手术过程。麻醉后，气管是通过一个半路上切口气管2软骨环之间进行插入插管插管。然后一个皮肤切口，在第二肋间水平上的左胸壁和肌肉层被清除，以找出主动脉的上升部分。升主动脉的收缩到其原始直径由应用的小尺寸钛夹的50-60％。以下主动脉缩窄，第二和第三肋近似prolene线缝合。气管插管被删除，一旦自主呼吸被重新建立。动物被允许恢复Ø通过逐渐降低麻醉n为加热垫。通过升主动脉的收缩产生的压力超负荷的强度是通过使用反式胸二维多普勒超声心动图记录的压力梯度来确定。总体来说，这一协议是逐渐发生和发展的代偿性心肌肥厚心脏衰竭阶段时，研究重塑事件和心脏的收缩特性非常有用。

在我们的实验中，我们能够实现80％以上的存活率。主动脉缩窄的效果是通过执行多普勒超声心动图证实。大鼠（N = 6），其在主动脉狭窄部位约60毫米汞柱的压力梯度，观察8周，处死以便分析心肌肥大的发展（ 图1）。 8周后手术后的超声心动图评价结果显示左心室参数，如跨室间隔厚度，左室后壁厚度及减少左室内径在舒张状态，动物，进行主动脉缩窄显著增加，较假手术对照组（...

Watch this Scientific Journal Video about Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model at JoVE.com

Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

我们描述了使用一个小的金属夹子由升主动脉缩窄建立压力负荷和左心室肥厚大鼠一个逐步的过程。该模型被广泛用于心肌肥厚过程中学习重塑变化，物色及评估策略，这种变化的回归。

大鼠建立压力超负荷心肌肥厚模型在升主动脉缩窄

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart ...

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17.0K 次观看.  Rajiv Gandhi Centre for Biotechnology. 我们描述了使用一个小的金属夹子由升主动脉缩窄建立压力负荷和左心室肥厚大鼠一个逐步的过程。该模型被广泛用于心肌肥厚过程中学习重塑变化，物色及评估策略，这种变化的回归。 

视频: Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model

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 ...

科研

医学

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 ...

A Model of Cardiac Remodeling Through Constriction of the Abdominal Aorta in Rats

Heart failure is one of the leading causes of death worldwide. It is a complex clinical syndromethat includes fatigue, dyspnea, exercise intolerance, and fluid retention. Changes in myocardial structure, electrical conduction, and energy metabolism develop with heart failure, leading to contractile dysfunction, increased risk of arrhythmias, and sudden death. Hypertensive heart disease is one of the key contributing factors of cardiac remodeling associated with heart failure. The most commonly-used animal model mimicking hypertensive heart disease is created via surgical interventions, such as by narrowing the aorta. Abdominal aortic constriction is a useful experimental technique to induce a pressure overload, which leads to heart failure. The surgery can be easily performed, without the need for chest opening or mechanical ventilation. Abdominal aortic constriction-induced cardiac pathology progresses gradually, making this model relevant to clinical hypertensive heart failure. Cardiac injury and remodeling can be observed 10 weeks after the surgery. The method described here provides a simple and effective approach to produce a hypertensive heart disease animal model that is suitable for studying disease mechanisms and for testing novel therapeutics.

A rat model of abdominal aortic constriction that induces cardiac hypertrophy and remodeling is described. An efficient, highly-reproducible, and minimally-invasive method is used to provide a simple yet useful platform for research in myocardial hypertrophy and dysfunction.

心脏重构通过大鼠腹主动脉缩窄的模型

Heart failure is one of the leading causes of death worldwide. It is a complex clinical syndromethat includes fatigue, dyspnea, exercise intolerance, and ...

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 ...

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

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to perform a partial thoracotomy to visualize the transverse aortic arch. However, the surgical trauma caused by the thoracotomy in open-chest models changes the respiratory physiology as the ribs are dissected and left unattached after chest closure. To prevent this, we established a minimally invasive, closed chest approach via lateral thoracotomy. Herein we approach the aortic arch via the 2nd intercostal space without entering the chest cavities, leaving the mouse with a less traumatic injury to recover from. We perform this operation using standard laboratory settings for open chest TAC procedures with equal survival rates. Apart from maintaining physiological breathing patterns due to the closed chest approach, the mice seem to benefit by showing rapid recovery, as the less invasive technique appears to facilitate a fast healing process and to reduce immune response after trauma.

Here, we present a protocol of Transverse Aortic constriction (TAC) via a lateral thoracotomy. This technique is a minimally invasive, closed chest surgical procedure aiming to simulate pressure overload and heart failure in mice utilizing standard TAC laboratory settings.

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 Pulmonary Trunk Banding Model of Pressure Overload Induced Right Ventricular Hypertrophy and Failure

Right ventricular (RV) failure induced by sustained pressure overload is a major contributor to morbidity and mortality in several cardiopulmonary disorders. Reliable and reproducible animal models of RV failure are therefore warranted in order to investigate disease mechanisms and effects of potential therapeutic strategies. Banding of the pulmonary trunk is a common method to induce isolated RV hypertrophy but in general, previously described models have not succeeded in creating a stable model of RV hypertrophy and failure.
We present a rat model of pressure overload induced RV hypertrophy caused by pulmonary trunk banding (PTB) that enables different phenotypes of RV hypertrophy with and without RV failure. We use a modified ligating clip applier to compress a titanium clip around the pulmonary trunk to a pre-set inner diameter. We use different clip diameters to induce different stages of disease progression from mild RV hypertrophy to decompensated RV failure.
RV hypertrophy develops consistently in rats subjected to the PTB procedure and depending on the diameter of the applied banding clip, we can accurately reproduce different disease severities ranging from compensated hypertrophy to severe decompensated RV failure with extra-cardiac manifestations.
The presented PTB model is a valid and robust model of pressure overload induced RV hypertrophy and failure that has several advantages to other banding models including high reproducibility and the possibility of inducing severe and decompensated RV failure.

We present a surgical method to induce right ventricular hypertrophy and failure in rats.

压力超载诱发右室肥厚和衰竭的肺动脉扣条柱模型

Right ventricular (RV) failure induced by sustained pressure overload is a major contributor to morbidity and mortality in several cardiopulmonary ...

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 ...

O-Ring Aortic Banding Versus Traditional Transverse Aortic Constriction for Modeling Pressure Overload-Induced Cardiac Hypertrophy

Aortic banding in mice is one of the most commonly used experimental models for cardiac pressure overload-induced cardiac hypertrophy and the induction of heart failure. The previously used technique is based on a threaded suture around the aortic arch tied over a blunted 27 G needle to create stenosis. This method depends on the surgeon manually tightening the thread and, thus, leads to high variance in the diameter size. A newly refined method described by Melleby et al. promises less variance and more reproducibility after surgery. The new technique, o-ring- aortic banding (ORAB), uses a non-slip rubber ring instead of a suture with a thread, resulting in reduced variation in pressure overload and reproducible phenotypes of cardiac hypertrophy. During surgery, the o-ring is placed between the brachiocephalic and left carotid arteries. Successful constriction is confirmed by echocardiography. After 1 day, correct placement of the ring results in an increased flow velocity in the transverse aorta over the o-ring-induced stenosis. After 2 weeks, impaired cardiac function is proven by decreased ejection fraction and increased wall thickness. Importantly, besides less variance in the diameter size, ORAB is associated with lower intra- and post-operative mortality rates compared with transverse aortic constriction (TAC). Thus, ORAB represents a superior method to the commonly used TAC surgery, resulting in more reproducible results and a possible reduction in the number of animals needed.

The present protocol describes a new technique of aortic banding in mice to induce pressure overload cardiac hypertrophy. For banding, a rubber ring with a fixed inner diameter is used. This new technique promises less variance and more reproducible data for future experiments.

O形环主动脉束带与传统横主动脉收缩在压力超负荷引起的心脏肥大建模中的比较

Aortic banding in mice is one of the most commonly used experimental models for cardiac pressure overload-induced cardiac hypertrophy and the induction of ...

Modified Heterotopic Abdominal Heart Transplantation and a Novel Aortic Regurgitation Model in Rats

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical technique. Modifying the transplantation procedure to strengthen the myocardial protection could prolong the ischemia time while preserving the donor&#39;s cardiac function. This technique&#39;s key points are as follows: transecting the donor&#39;s abdominal aorta before harvesting to unload the donor&#39;s heart; perfusing the donor&#39;s coronary arteries with a cold cardioplegic solution; and topical cooling of the donor&#39;s heart during the anastomosis procedure. Consequently, since this procedure prolongs the acceptable ischemia time, beginners can easily perform it and achieve a high success rate.
Moreover, a new aortic regurgitation (AR) model was established in this work using a technique different from the existing one,&#160;which is created by inserting a catheter from the right carotid artery and puncturing the native aortic valve under continuous echocardiographic guidance. A heterotopic abdominal heart transplantation was performed using the novel AR model. In the protocol, after the donor&#39;s heart is harvested, a stiff guidewire is inserted into the donor&#39;s brachiocephalic artery and advanced toward the aortic root. The aortic valve is punctured by pushing the guidewire further even after the resistance is felt, thus inducing AR. It is easier to damage the aortic valve using this method than with the procedure described in the conventional AR model. Additionally, this novel AR model does not contribute to the recipient&#39;s circulation; therefore, this method is expected to produce a more severe AR model than the conventional procedure.

This study demonstrates a reproducible heterotopic abdominal heart transplantation technique in rats that beginners can learn and perform. Additionally, a novel aortic regurgitation model in rats is generated by performing heterotopic abdominal heart transplantation and damaging the donor's aortic valve using a guidewire after harvesting.

改良异位腹心移植及新型大鼠主动脉瓣反流模型

Over the past 50 years, many researchers have reported heterotopic abdominal heart transplantation in mice and rats, with some variations in the surgical ...