Name: ascending aortic constriction in rats for creation of pressure overload cardiac hypertrophy model
Uploaded: 2014-06-29T14:00:00
Description: Watch this Scientific Journal Video about Ascending Aortic Constriction in Rats for Creation of Pressure Overload Cardiac Hypertrophy Model at JoVE.com

The authors acknowledge Department of Biotechnology, Government of India for financial support of this project. Ajith Kumar G S was supported with senior research fellowship from Council of Scientific and Industrial Research, Government of India and Binil Raj with senior research fellowship from Indian Council of Medical Research, Government of India.

Animal experiments were performed after obtaining approval from the Institutional Animal Ethics Committee. Wistar rats were housed under a 12 hr&#160;dark to light cycle, constant room temperature (24 &#177; 2 &#176;C) with food and water ad libitum (as per the CPCSEA guidelines).
1) Pre-operative Care and Anesthesia
<ol>
	<li>Keep rat (approximately 200 g&#160;body weight) under antibiotic umbrella 24 hr&#160;before surgery by administering amoxicillin orally (dose: 500 mg/L of water).</li>...

<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>

There are several surgical models for the induction of pressure overload as well as cardiac hypertrophy and heart failure. In small animals, Lorell and colleagues developed the model we have described here and they reported the occurrence of compensated cardiac hypertrophy 8 weeks post aortic banding5. Cardiac changes gradually progress to a decompensated state and then result in heart failure. The main advantage of this model is the gradual onset of increase in left ventricular pressure and thus similar to cl...

Small animal models are the most preferred tools for the study of chronic changes in the development of cardiac hypertrophy and its progression to heart failure. Heart failure models by surgical methods were originally developed in rats as these animals are most suitable for open chest surgical procedures, echocardiography and evaluation of hemodynamic parameters. They also provide adequate post mortem samples for tissue, cellular and molecular level studies1. Constriction of the ascending aorta is one of the most common and successful surgical models for creating pressure overload heart failure2,3. This model is well suited to study the cellular and sub cellular remodeling events and contractile properties of the heart during the transition from hypertrophy to heart failure4.
A major advantage of this model is the gradual onset of pressure overload on the heart5,6. This model is clinically relevant because of its slow but steady progression from compensated cardiac hypertrophy to decompensated phase and finally to the heart failure stage. The duration for progression of cardiac hypertrophy to heart failure and the associated physiological changes are mainly influenced by the degree of stenosis produced7. Ascending aortic constriction can be performed in two ways, either by using sutures or by application of metallic clips8,9. The main advantage of using a metallic clip for aortic constriction is that the surgical procedures are less complicated. In this method one has to locate the supra valvular ascending aorta and insert the clip around the aorta to obtain desired level of constriction. A chest retractor is not necessary in this procedure. Aortic banding by suturing requires more surgical manipulations for placing the gauge needle beside the ascending aorta and suturing around it to produce the desired level of aortic constriction. The latter technique is more time consuming when compared with the use of metallic clips for aortic constriction. The method described in this video demonstrates the surgical procedure for ascending aortic constriction in rats that allows creation of pressure overloaded left ventricular hypertrophy model.

<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

Ascending aortic constriction is the most common and successful surgical model for creating pressure overload induced cardiac hypertrophy and heart failure. Here, we describe a detailed surgical procedure for creating pressure overload and cardiac hypertrophy in rats by constriction of the ascending aorta using a small metallic clip. After anesthesia, the trachea is intubated by inserting a cannula through a half way incision made between two cartilage rings of trachea. Then a skin incision is made at the level of the second intercostal space on the left chest wall and muscle layers are cleared to locate the ascending portion of aorta. The ascending aorta is constricted to 50&#8211;60% of its original diameter by application of a small sized titanium clip. Following aortic constriction, the second and third ribs are approximated with prolene sutures. The tracheal cannula is removed once spontaneous breathing was re-established. The animal is allowed to recover on the heating pad by gradually lowering anesthesia. The intensity of pressure overload created by constriction of the ascending aorta is determined by recording the pressure gradient using trans-thoracic two dimensional Doppler-echocardiography. Overall this protocol is useful to study the remodeling events and contractile properties of the heart during the gradual onset and progression from compensated cardiac hypertrophy to heart failure stage.

In our experiments we are able to achieve more than 80% survival rates. The effectiveness of aortic constriction was confirmed by performing Doppler echocardiography. Rats (n=6) with a pressure gradient of about 60 mm of Hg at the aortic constricted site were observed for 8 weeks and sacrificed to analyze for the development of cardiac hypertrophy (Figure 1). After 8 weeks post-surgery echocardiographic evaluation revealed a significant increase in left ventricular parameters such as inter ventricular se...

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

We describe a stepwise procedure for creating pressure overload and left ventricular hypertrophy in Wistar rats by constriction of the ascending aorta using a small metallic clip. This model is extensively used for studying remodeling changes during cardiac hypertrophy and for identifying and evaluating strategies for regression of such changes.

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

Research

JoVE Journal

Medicine

Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, ...

Measuring Ascending Aortic Stiffness In Vivo in Mice Using Ultrasound

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...