Yazarlar, bu projenin mali destek için Biyoteknoloji Bölümü, Hindistan Hükümeti kabul. Ajith Kumar GS Bilimsel ve Tıbbi Araştırma, Hindistan Hükümeti Hint Konseyi kıdemli araştırma bursu ile Endüstriyel Araştırma, Hindistan Hükümeti ve Binil Raj Konseyi kıdemli araştırma bursu ile desteklenmiştir.

Hayvan deneyleri Kurumsal Hayvan Etik Kurul onayı alındıktan sonra yapıldı. Wistar sıçanları, ışık çevriminin (CPCSEA yönergelere göre) yiyecek ve su ad libitum ile sürekli oda sıcaklığında (24 ± 2 ° C) ile, 12 saat karanlık altında muhafaza edilmiştir. 1) Ameliyat öncesi Bakım ve Anestezi <ol><li> (: Su 500 mg / L doz) oral amoksisilin uygulanması ile ameliyattan önce antibiyotik şemsiye 24 saat sıçan altında (yaklaşık olarak 200 g vücut ağırlığı) tutun. </li><li> 15 dakika boyunca 121 ° C&#39;de otoklav ile (örneğin makas, forseps, klip aplikatör, dikiş iğneleri ve iğne tutucu gibi) tüm cerrahi aletleri sterilize edin. </li><li> Kalp hızında hızlı bir düşüş önlemek için 37 ° C civarında hayvanlar vücut ısısını korumak için bir ısıtma pedi kullanın. </li><li> Ameliyat öncesi ve sırasında hayvanın dehidratasyonu önlemek için özen gösterin. </li><li> Ile karıştırılmış% 3 izofluran ile bir indüksiyon odası içindeki sıçan anestezisi0.5-1.0 L / dk% 100 oksijen; % 1.5 izofluran ile anestezi korumak. </li><li> Başarılı anestezi onaylamak için pedal refleksini kontrol edin. </li></ol> Cerrahi Sitenin 2) hazırlanması <ol><li> Sırtüstü pozisyonda sıcaklık kontrollü bir ısıtma yastığı üstüne sıçan tutun. </li><li> Bir burun konisi ile anestezi korurken pozisyonda hayvan tutmak için sıçan ön dişlerin üzerine bir lastik bant yerleştirin. </li><li> Yaka kürk çıkarın ve (tercihen bir elektrikli tıraş makinesi kullanarak) sıçan göğüs bölgesini bıraktı. </li><li> Sonra povidon-iyot solüsyonu ve% 70 etil alkol ile birlikte cerrahi siteyi dezenfekte edin. </li><li> Ameliyat prosedürü sırasında sadece cerrahi sitesini ortaya çıkarmak için steril bir örtü kullanın. Not: hayvan bakımı için ek bir seçenek olarak,% 0.25 bupivakain ID (2.5 mg / kg) önce lokal anestezi / analjezi için her kesi yerinde incising için dahil edilebilir. </li></ol> Rat 3) Trakeal Entübasyon <ol><li> Steril bir cerrahi bıçak kullanarak trakea cilt paralel küçük bir kesi yapmak ve dikkatle trakea maruz amacıyla altta yatan doku ayırmak. </li><li> Trakea altında 4-0 ipek dikiş ipliğinin bir kravat uygulayın ve nazikçe yukarı kravat yükseltmek. </li><li> İki kıkırdak halkaları arasında bir yarım kesi yapmak ve sıçan trakea içine trakeal kanül takın. </li><li> / Dakika, 1.70 ml tidal hacmi ve (200 g vücut ağırlığına sahip bir sıçan için) 0,60 saniye inspirasyon süresi 50 solukluk bir solunum hızı sağlamak için bir kemirgen vantilatör için trakeal kanülün bağlayın. </li></ol> Artan Aort 4) daraltma <ol><li> Parmaklarıyla kaburga konumunu algılamak sonra, ikinci ve üçüncü kaburga arasındaki sol göğüs duvarı yaklaşık 2 cm&#39;lik bir cilt insizyonu olun. </li><li> Tabakası ile interkostal kaslar tabakanın ayrılması ve ikinci ve üçüncü kaburga arasında yaklaşık 1,5 cm uzunluğunda bir kesi yapar. (Bakım almak olmalıdırkaburgalar arasında kesi yaparken akciğerlere herhangi bir yaralanmayı önlemek için n) </li><li> Kaburga geri çekin ve aort artan bölümünü bulun. </li><li> Orijinal çapının% 50-60 aortu daraltıcı sayede bir aplikatör yardımıyla çıkan aort etrafında küçük ölçekli titanyum klip yerleştirin. </li><li> Aort daralma sonra kesikli bir dikiş desen 3.0 prolen ile ikinci ve üçüncü kaburga yaklaşmaktadır. Aynı zamanda, akciğerleri yeniden şişirmek için yaklaşık 2-4 saniye boyunca ventilatör duraklama. </li><li> 3.0 prolen sütür ve kesintiye dikiş desen 4,0 ipek dikişlerle deri ile kas tabakaları appose. Sentetik olmayan emilebilir dikişlerle deri dikilmesi için yerine ipek kullanılabilir. </li><li> Bir kez spontan solunum yeniden kurulur sıçan trakeal kanül çıkarın. </li><li> 3,0 prolen dikiş ve 4.0 ipek dikiş ile deri tabakası ile birlikte trakea açıklığı kapatın. </li><li> Hayvan t kurtarmak için izino yavaş yavaş anestezi ve ventilatör destekli solunum düşürerek ped ısıtma. </li><li> Yaştaki sham kontrol hayvanlarında, çıkan aortun daralması yapmadan trakeotomi ve torakotomi gerçekleştirin. </li></ol> 5) post-operatif Bakım <ol><li> Povidon-iyot solüsyonu ile cerrahi bölgeyi dezenfekte edin. </li><li> Ameliyat sonrası analjezi için, 1 hafta (10 mg / kg vücut ağırlığı / gün) tramadol intra-peritoneal olarak enjekte edilir. </li><li> Dehidratasyon bulguları cerrahi (yaklaşık 1 ml) sonra ortaya çıkarsa, steril serum fizyolojik intraperitoneal olarak enjekte edilir. </li><li> Yedi gün (: su 500 mg / L doz) için, karışık içme suyu ile ağızdan amoksilin uygulayın. </li><li> Inhalasyon anestezi altında ameliyat sonrası 10 gün, deriden kalan ipek sütür çıkarın. </li></ol> Artan Aort Başarılı Konstrüksiyon 6) Onayı <ol><li> INTEN belirlemek için bir trans-torasik iki boyutlu Doppler ekokardiyografi-gerçekleştirinartan aort daralma tarafından üretilen basınç yüklenmesinin versitesi. </li><li> Daha önce tarif edildiği gibi, dişi bir hafta ameliyat sonrası anestezisi (adım 1.5) </li><li> Çıkan aort tahditli bölümü boyunca basınç gradyanı kaydetmek için yukarıda sternal konumunda ultrason transdüktörü yerleştirin. Not: aort dar yerinde Hg yaklaşık 60 mm&#39;lik bir basınç gradyanı ile sıçanlar yaklaşık 8-10 hafta ameliyattan tarafından ciddi kardiyak hipertrofisi gelişir. </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>

Yazarlar ifşa hiçbir şey yok.

Basınç yüklenmesinin indüksiyon yanı sıra kalp hipertrofisi ve kalp yetmezliği için çeşitli cerrahi modelleri vardır. Küçük hayvanlarda, Lorell ve arkadaşları burada anlattığımız model geliştirdi ve kompanse kardiyak hipertrofisi 8 hafta sonrası aort bağlama 5 geçtiği bildirildi. Kardiyak değişikliklerin yavaş yavaş bir dekompanse duruma ilerleme ve sonra kalp yetmezliği ile sonuçlanabilir. Bu modelin en büyük avantajı, sol ventrikül basıncı artışı ve hipertansiyon, kro...

Küçük hayvan modelleri, kardiyak hipertrofisi, kalp yetmezliği olan ilerleme gelişiminde kronik değişikliklerin çalışma için en çok tercih edilen araçlardır. Bu hayvanların açık göğüs cerrahi işlemler, hemodinamik parametreler ekokardiyografi ve değerlendirilmesi için en uygun olduğu gibi cerrahi yöntemlerle kalp yetmezliği modelleri orijinal olarak, sıçanlarda geliştirilmiştir. Onlar da hücresel doku ve moleküler düzeyde çalışmalar için 1 yeterli otopsi örnekleri sağlar. Çıkan aort darlığı basınç yüklenmesi kalp yetmezliği 2, 3 oluşturmak için en yaygın ve başarılı cerrahi modellerinden biridir. Bu model de hipertrofisi, kalp yetmezliği 4 geçiş sırasında hücresel ve alt hücresel yeniden olaylar ve kalbin kasılma özelliklerini incelemek için uygundur. Bu modelin önemli bir avantajı, kalp 5 üzerindeki basınç yüklenmesinin kademeli başlangıcıdır &lt;/&gt; 6 sup. Bu model, telafi kalp hipertrofiden dekompanse safhada ve nihayet kalp yetmezliği aşamasına yavaş ama istikrarlı bir ilerleme klinik olarak önemlidir. Kalp yetersizliği ve ilgili fizyolojik değişikliklere kardiyak hipertrofisi ilerlemesi için süresi esas olarak 7 üretilen stenoz derecesine etkilenmektedir. Artan sıkışma aort dikiş kullanarak ya da metal klipler 8, 9 uygulanmasıyla ya da iki şekilde yapılabilir. Aort daralma için bir metalik klip kullanmanın ana avantajı cerrahi daha az karmaşık olmasıdır. Bu yöntemde bir supra kapak çıkan aort bulmak ve daralma istenen seviyede elde etmek aort etrafında klibi eklemek zorundadır. Bir göğüs ekartör Bu prosedürde gerekli değildir. Dikiş ile aort bağlama çıkan aort yanında iğne yerleştirerek ve çevresinde dikilmeye daha fazla cerrahi manipülasyonlar gerektiriraort daralma istenilen düzeyde üretir. İkinci teknik aort daralması için metalik klip kullanımı ile karşılaştırıldığında, daha zaman alıcı olan. Bu video açıklanan yöntem oluşturma basıncı aşırı sol ventrikül hipertrofisi modeli sağlar: farelerde aort daralma artan için cerrahi prosedür gösterir.

<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

Aort daralma Artan kardiyak hipertrofi ve kalp yetmezliği kaynaklı aşırı basınç oluşturmak için en yaygın ve cerrahi başarılı bir modeldir. Burada, küçük bir metalik klip kullanarak çıkan aortun daralması ile sıçanlarda basınç aşırı ve kardiyak hipertrofisi yaratmak için detaylı bir ameliyat prosedürü tarif. Anestezi sonrasında, trakea trakea iki kıkırdak halkaları arasında yapılan bir yarım kesi yoluyla bir kanül sokularak entübe edilir. Sonra bir cilt kesi sol göğüs duvarında ikinci interkostal alanı düzeyinde yapılır ve kas tabakaları aort artan kısmını bulmak için temizlenir. Aorta, küçük boyutlu titanyum klibi uygulaması ile orijinal çapının% 50-60 daraltılmıştır. Aort daralma sonra, ikinci ve üçüncü prolen kaburga dikiş ile yaklaştırılır. Trakeal kanül çıkarıldıktan sonra spontan solunum yeniden kurulmuştur. Hayvan o geri bırakılıryavaş yavaş anestezi düşürerek ısıtma pedi n. Çıkan aort daralma yarattığı basınç yüklenmesinin yoğunluğu trans-torasik iki boyutlu Doppler-ekokardiyografi ile basınç degrade kayıt tarafından belirlenir. Genel olarak bu protokol, kalp yetmezliği aşamasına telafi kardiyak hipertrofinin arasındaki aşamalı başlangıcı ve gelişimi sırasında yeniden etkinliklerle kalbin kasılma özelliklerini incelemek için yararlıdır.

Deneylerde biz fazla% 80 sağkalım oranları elde edebiliyoruz. Aort daralma etkinliği Doppler gerçekleştirilerek teyit edilmiştir. Fareler (n = 6), aort daralma yerinde Hg ile yaklaşık 60 mm arasında bir basınç gradyanı ile 8 hafta boyunca gözlenmiştir ve kardiyak hipertrofi geliştirilmesi (Şekil 1) analiz etmek için kurban edilmiştir. 8 hafta sonra ameliyat sonrası ekokardiyografik değerlendirme sham ameliyat ile karşılaştırıldığında, bu tür aort daralma uygulanan hayvanlar...

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

Biz küçük bir metalik klip kullanarak çıkan aortun daralması ile Wistar sıçanlarda basınç aşırı ve sol ventrikül hipertrofisi oluşturmak için adım adım bir prosedür açıklanmaktadır. Bu model yaygın olarak kalp büyümesi sırasında yeniden değişiklikleri incelemek için ve bu değişikliklerin regresyonu için stratejiler belirlenmesi ve değerlendirilmesi için kullanılmaktadır.

Basınç Aşırı Kardiyak hipertrofi Modeli Oluşturma Ratlarda Aort daralma, Artan

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

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JoVE Journal

Medicine

17.0K Görüntüleme.  Rajiv Gandhi Centre for Biotechnology.  Biz küçük bir metalik klip kullanarak çıkan aortun daralması ile Wistar sıçanlarda basınç aşırı ve sol ventrikül hipertrofisi oluşturmak için adım adım bir prosedür açıklanmaktadır. Bu model yaygın olarak kalp büyümesi sırasında yeniden değişiklikleri incelemek için ve bu değişikliklerin regresyonu için stratejiler belirlenmesi ve değerlendirilmesi için kullanılmaktadır. 

Video: 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.

Farelerde Basınç Aşırı Modeli Koroner Arter Akış ve Koroner Akım Rezervi Ultrason Dayalı Değerlendirme

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

Tıp

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.

Ekokardiyografik Imaging tarafından Enine Aort Konstrüksiyon Mouse Modeli Kardiyak Morfolojik Değerlendirilmesi ve Fonksiyonel Değişiklikler

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.

Sıçanlarda Karın Aort Konstrüksiyon sayesinde Kardiyak Yaptırma Bir Model

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.

Farelerde Minimal İnvaziv Enine Aort Konstrüksiyon

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.

Minimal invaziv transvers aort daralma farelerde sol ventrikül hipertrofisi indüksiyon için tekniği

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.

Transvers aort daralma farelerde ikna etmek için kapalı-göğüs manken

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.

Sağ ventrikül hipertrofisi ve başarısızlık bir pulmoner gövde basınç yükünün modeli bantlama indüklenen

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.

Geçici Miyokard Hipertrofisi Elde Etmek için Emilebilir Dikiş ile Enine Aort Daralmasını Çalıştırma

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-Ring Aort Bantlamasına Karşı Geleneksel Transvers Aort Daralması Basınç Aşırı Yüküne Bağlı Kardiyak Hipertrofinin Modellenmesi İçin

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.

Modifiye Heterotopik Abdominal Kalp Transplantasyonu ve Sıçanlarda Yeni Bir Aort Yetersizliği Modeli

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