The authors have nothing to disclose.

プロトコルは、ワシントン大学の施設内動物管理使用委員会のガイドラインに従います。 1.手術手順およびイメージングのための準備<ol><li> TACまたは偽手術の対象とC57BL / 6マウスは、以前に10を説明しました。 </li><li>一週間TACまたは偽手術後、1リットル/分のO 2を混合し、2％イソフルランで誘導チャンバ内でマウスを麻酔。つま先や尾のピンチに無反応により適切な麻酔を確認してください。麻酔下ながら乾燥を防ぐために、目に獣医の軟膏を使用してください。脱毛クリームを適用することにより、胸毛を削除してください。 70％エタノールでマウスの皮膚を消毒します。 </li><li>仰臥位で動物取扱プラットフォームにマウスを固定します。 1リットル/分のO 2と混合した1％イソフルラン-麻酔の安定したレベルを維持するために、0.5を提供するためにノーズコーンを使用しています。 </li><li>マウスの足に電極ゲルを適用し、電極パッドにそれらをテープ。 </li><li>体温を監視するための直腸プローブを挿入します。加熱パッドまたはランプを経由して37℃の体温を維持。 </li><li>マウス胸、心臓を覆う主領域に予熱した超音波ゲルの層を適用します。注：超音波ゲルを除去し、イメージング処理後、滅菌ガーゼでマウスを乾かします。 </li></ol>大動脈弓ビューで、[使用するBモードとドップラーイメージングは​​、横大動脈狭窄を評価します<ol><li>大動脈、主要幹線分岐し、狭窄部位を可視化するために、大動脈弓のビューを取得するためにBモードの設定を使用します。 <ol><li>左側臥位にマウスを回転させることが可能な限りプラットフォームの左側を傾けます。垂直位置で待機することにより、超音波トランスデューサを持ち、ノッチがマウスのあごに向いて、右傍胸骨ラインに沿って胸の上に置きます。注：transdを下げたときに、マウスの胸部を圧縮しないでください。ucer;圧力の最小量が必要とされます。 </li><li>肩甲骨のレベルでトランスデューサを傾け、大動脈弓が見えてくるまで少し時計回りに回転。腕頭動脈（IA）および左総頸動脈（LCCA）（ 図1）の分岐との間に配置される横方向の大動脈狭窄部位を観察します。 注：いいえくびれは、偽手術マウスでは検出されませんでした。 </li></ol></li><li>狭窄サイト全体の血流の方向と速度を監視するために、カラードプラモードに切り替えるには、ワークステーションの「カラードップラー」ボタンをクリックします。 「シネストア」ボタンをクリックして画像を取得し、保存します。 </li><li>最高速度で狭窄ジェットを検索するための狭窄部位のすぐ遠位波ドプラモード、および場所のサンプルボリューム（破線のカーソルボックス）パルスに切り替えるに「PWドップラー」ボタンをクリックし、「PWド​​ップラー」ボタンをクリックしてください大動脈FLの波形を取得しますOWとメジャーピーク速度（ 図2）。 </li><li>圧力勾配= 4×V maxの2：変更されたベルヌーイの式を用いて狭窄サイト全体の圧力勾配を計算します。唯一の更なる分析のために40〜80 mmHgの範囲の圧力勾配をマウスに含まれています。 </li></ol>傍胸骨長軸ビューで、[使用するBモードとMモードイメージングは​​、心臓寸法及び収縮を評価します<ol><li>マウスがプラットフォーム上で仰臥位で横たわっていると、ノッチは、マウスの頭を指している垂直な方法でトランスデューサーを保持します。左胸骨傍のラインに胸部平行にトランスデューサを下げ、30°反時計回りに回転させます。 </li><li>心の完全長軸「サジタル」ビューを得るために、Bモードイメージングを使用してください。トランスデューサの角度を調整し、左心室、室内隔壁、および右心室壁のわずかな部分を可視化する深さに焦点を当てます。 S心臓壁の厚さおよびチャンバ寸法の後の測定用の画像をaveの。このようなIVSまたはLVAW、LVID、およびLVPWなどの選択パラメータは、「心臓パッケージ」を使用して、その後、測定値を得るために、各パラメータに対応する線を描画するには画像をクリックしてください。 </li><li>心臓壁運動パターンを観察し、無動、運動低下、および非同期性を含む可能性運動異常、かどうかを確認します。 注：無動と運動低下は、心臓壁の動きの完全および部分的な損失を示し、それぞれ。非同期は、不規則な、まとまりのない心臓壁の動きを示しています。 </li><li>乳頭筋のレベルでLVの壁に垂直にMモード、場所Mモードカーソルに切り替えて、心臓の寸法および短縮率（ 図3）の後の測定のための画像を取得します。 </li></ol>傍胸骨短軸ビュー、心臓形態と機能を評価するために使用するBモードとMモードイメージング4. <ol><li>金曜日オム傍胸骨長軸ビューは、トランスデューサ90°時計回りに回転させることにより、胸骨傍短軸像を得ます。はっきりと見えると右（2と4時の位置）に位置する乳頭筋の両方で、Bモードで心臓の水平断面「横」ビューを提供するために、トランスデューサを調整します。 </li><li> Mモードに切り替えて、左心室のミッドレベルでMモードの軸を配置します。心臓壁の厚さ、チャンバーの寸法、および短縮率（ 図4）の後の測定のために画像を取得して保存。 IVSまたはLVAW、LVID、およびLVPW含む「心臓パッケージ」、SAXでの選択パラメータ（短軸）を使用し、測定値を得るために、各パラメータに対応する線を描画するには画像をクリックしてください。 注：ここで得られた測定値は、傍胸骨長軸ビュー（ 図5）で得られたものと密接に相関するはずです。 </li></ol>アピカル四腔像、使用5.収縮期および拡張期機能を評価するためにドップラーイメージング<ol><li>画面下部の心房と左と右の両方の心室を視覚化するために心尖部四腔像を取得します。 Bモードでは、短軸像から、ダウン角にマウスの頭を、プラットフォームの左上隅を傾け、マウスの右の肩に向けてトランスデューサを向けます。これは頂点に向かって見上げる心の「冠状」ビューを達成するために本質的です。 </li><li> Bモードで僧帽弁を可視化し、カラードプラモードに切り替えて、僧帽弁の先端に試料容量（破線カーソルボックス）を配置します。 </li><li>僧帽弁を横切る流れのパターンを評価するためにPWドプラモードに切り替えます。僧帽弁血流の方向にドップラープローブカーソルを平行に合わせます。ピーク速度（ 図6）を決定するためにプローブの角度20°未満を使用してください。 </li><li>後で測定のための画像を保存します。 「心臓パッケージ」を使用し、選択して &quot;MV流れ。「各パラメータをクリックして、測定値を得るために、対応する線を描画可能な測定は、次のとおりです。ピークE速度（初期のアクティブ心室弛緩を充填）、速度（心房収縮と後半充填）ピーク、僧帽弁等容性弛緩と収縮時間（IVRTをし、それぞれIVCT）、および駆出時間（ET）。 </li><li> MPI =（IVCT + IVRT）/ ETにより心筋の性能指数（MPI）を計算します。 </li></ol>動物の6.術後の治療<ol><li>必要なときに腹腔内手術用動物に鎮痛および/または滅菌生理食塩水を与えます。 </li><li>動物が腹臥位に加熱パッド上で回復させます。それは胸骨横臥位を維持するのに十分な意識を取り戻したまで無人の動物を放置しないでください。完全に回復するまで、他の動物の会社に手続きを経た動物を返さないでください。 </li></ol>

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	<li>Rockman, H. 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=Segregation+of+atrial-specific+and+inducible+expression+of+an+atrial+natriuretic+factor+transgene+in+an+in+vivo+murine+model+of+cardiac+hypertrophy.">Segregation of atrial-specific and inducible expression of an atrial natriuretic factor transgene in an in vivo murine model of cardiac hypertrophy.</a> Proc Natl Acad Sci USA. 88 (18), 8277-8281 (1991).</li><li>Tanaka, N., 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=Transthoracic+echocardiography+in+models+of+cardiac+disease+in+the+mouse.">Transthoracic echocardiography in models of cardiac disease in the mouse.</a> Circulation. 94 (5), 1109-1117 (1996).</li><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 (2), 138-144 (2009).</li><li>Heineke, J., Molkentin, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+cardiac+hypertrophy+by+intracellular+signalling+pathways.">Regulation of cardiac hypertrophy by intracellular signalling pathways.</a> Nat Rev Mol Cell Biol. 7 (8), 589-600 (2006).</li><li>Oka, T., 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=Cardiac-specific+deletion+of+Gata4+reveals+its+requirement+for+hypertrophy,+compensation,+and+myocyte+viability.">Cardiac-specific deletion of Gata4 reveals its requirement for hypertrophy, compensation, and myocyte viability.</a> Circ Res. 98 (6), 837-845 (2006).</li><li>Gardin, J. M., Siri, F. M., Kitsis, R. N., Edwards, J. G., Leinwand, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+assessment+of+left+ventricular+mass+and+systolic+function+in+mice.">Echocardiographic assessment of left ventricular mass and systolic function in mice.</a> Circ Res. 76 (5), 907-914 (1995).</li><li>Respress, J. L., 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=Transthoracic+echocardiography+in+mice.">Transthoracic echocardiography in mice.</a> J Vis Exp. (39), e1738 (2010).</li><li>Pistner, A., Belmonte, S., Coulthard, T., Blaxall, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+echocardiography+and+ultrasound+imaging.">Murine echocardiography and ultrasound imaging.</a> J Vis Exp. (42), e2100 (2010).</li><li>Patten, R. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+cardiac+function+using+pressure-volume+conductance+catheter+technique+in+mice+and+rats.">Measurement of cardiac function using pressure-volume conductance catheter technique in mice and rats.</a> Nat Protoc. 3 (9), 1422-1434 (2008).</li><li>Larsen, T. S., 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=The+isolated+working+mouse+heart:+methodological+considerations.">The isolated working mouse heart: methodological considerations.</a> Pflugers Arch. 437 (6), 979-985 (1999).</li><li>Roth, D. M., Swaney, J. S., Dalton, N. D., Gilpin, E. A., Ross, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+anesthesia+on+cardiac+function+during+echocardiography+in+mice.">Impact of anesthesia on cardiac function during echocardiography in mice.</a> Am J Physiol Heart Circ Physiol. 282 (6), H2134-H2140 (2002).</li><li>Pearlman, A. S., Stevenson, J. G., Baker, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doppler+echocardiography:+applications,+limitations+and+future+directions.">Doppler echocardiography: applications, limitations and future directions.</a> Am J Cardiol. 46 (7), 1256-1262 (1980).</li><li>Bauer, M., 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=Echocardiographic+speckle-tracking+based+strain+imaging+for+rapid+cardiovascular+phenotyping+in+mice.">Echocardiographic speckle-tracking based strain imaging for rapid cardiovascular phenotyping in mice.</a> Circ Res. 108 (8), 908-916 (2011).</li></ol>

This work was supported in part by NIH/NHLBI grants R00HL0908076 and R01HL116507 (to Q.L.).

心エコー検査は、広く心疾患2,6の齧歯類モデルにおいて心機能を評価するために使用されてきました。このような圧力-容積ループ測定11などの侵襲的または端末の方法論などに比べると、ex vivoでの心臓12は 、心エコー検査は、生きている動物で進行中の心臓の構造的および機能的変化を評価するための強力な、非侵襲的なツールを提供して取り組んでいます。...

Mouse models of heart disease, such as TAC and myocardial infarction (MI), have been proven to be valuable to study disease mechanisms as well as to develop novel therapeutic strategies3. TAC initially induces compensatory hypertrophy, but prolonged pressure overload leads to cardiac dilatation and heart failure4. The tightness of the aortic constriction directly determines the degree of cardiac hypertrophy and its transition to heart failure. Noninvasive and reliable measurement of pressure gradient across the aortic constriction is essential for the success of these studies. Doppler imaging has been used to assess pressure gradient produced by TAC5, which is a noninvasive alternative for catheter-based pressure measurement.
Echocardiography has been widely used to noninvasively measure cardiac morphology as well as systolic and diastolic function in mice6-8. Two-dimensional B-mode imaging is used to detect abnormal movements or structural changes of the heart. One-dimensional M-mode imaging is used for quantification of cardiac dimensions and contractility. Color and PW Doppler imaging has recently been used on rodent ultrasound, which has broad applications for echocardiography, including measurement of flow directionality and velocity, as well as systolic and diastolic performance9. 
Longitudinal real-time monitoring of cardiac function using echocardiography in B-mode, M-mode, color and PW Doppler mode provides comprehensive assessment of cardiac structure and function in mice under physiological and pathological conditions. Here we provide a detailed description of the use of echocardiographic imaging to monitor dynamic cardiac morphological and functional changes in mice following TAC or sham surgery.

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	<tbody>
		<tr height="41">
			<td height="41" style="height:41px;width:339px;">Anesthesia equipment</td>
			<td style="width:343px;">Harvard Apparatus, 84 October Hill Road 
			Holliston, MA</td>
			<td style="width:175px;">723015</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:339px;">Vevo 2100 Imaging System</td>
			<td style="width:343px;">VisualSonics Inc., 3080 Yonge Street Suite 6100, Box 66, Toronto, Ontario, Canada</td>
			<td style="width:175px;">Vevo 2100</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:339px;">Aquasonic ultrasound gel</td>
			<td style="width:343px;">Parker Laboratories, 286 Eldridge Rd, Fairfield, NJ&#160;</td>
			<td style="width:175px;">03-50</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:339px;">Isoflurane</td>
			<td style="width:343px;">Piramal Healthcare, Inc, 3950 Schelden Circle 
			Bethlehem, PA&#160;</td>
			<td style="width:175px;">NDC 66794-017-25</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:339px;">F/air anesthesia gas filter unit</td>
			<td style="width:343px;">A.M. Bickford, Inc, 12318 Big Tree Rd, Wales Center, NY&#160;</td>
			<td style="width:175px;">80120</td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

図1は、偽（ 図1A）に供したマウスの心臓またはTAC手術（ 図1B）の大動脈弓図のBモード画像を示しています。大動脈弓、腕頭動脈は、総頸動脈を左、および左鎖骨下動脈が示されています。大動脈狭窄は、TACにはっきりと見えることに注意してくださいが、心を偽ません。大動脈のビューからのカラードップラー画像は、 ?...

Watch this Scientific Journal Video about Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging at JoVE.com

Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

このプロトコルの目的は、非侵襲的B-およびMモード心エコー法およびカラー/脈波ドップラーイメージングを用いて、横方向の大動脈狭窄によって作成された心臓病のマウスモデルにおいて心臓の構造的および機能的変化を評価することです。

心臓形態学的および心エコーイメージングによって横大動脈狭窄のマウスモデルにおける機能の変更の評価

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable ...

assessment-cardiac-morphological-functional-changes-mouse-model

Research

JoVE Journal

Medicine

18.1K ビュー.  University of Washington. このプロトコルの目的は、非侵襲的B-およびMモード心エコー法およびカラー/脈波ドップラーイメージングを用いて、横方向の大動脈狭窄によって作成された心臓病のマウスモデルにおいて心臓の構造的および機能的変化を評価することです。 

ビデオ: Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

Echocardiographic Assessment of the Right Heart in Mice

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential therapies. Given the expense and time involved in creating animal models of disease, it is critical that researchers have tools to accurately assess phenotypic expression of disease. Right ventricular dysfunction is the major manifestation of pulmonary hypertension. Echocardiography is the mainstay of the noninvasive assessment of right ventricular function in rodent models and has the advantage of clear translation to humans in whom the same tool is used. Published echocardiography protocols in murine models of PAH are lacking.
In this article, we describe a protocol for assessing RV and pulmonary vascular function in a mouse model of PAH with a dominant negative BMPRII mutation; however, this protocol is applicable to any diseases affecting the pulmonary vasculature or right heart. We provide a detailed description of animal preparation, image acquisition and hemodynamic calculation of stroke volume, cardiac output and an estimate of pulmonary artery pressure.

This article provides a protocol for the echocardiographic assessment of right ventricular size and pulmonary hypertension in mice. Applications include phenotype determination and serial assessment in transgenic and toxin-induced mouse models of cardiomyopathy and pulmonary vascular disease.

マウスの右心の心エコー評価

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential ...

医学

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.

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.

圧負荷心肥大モデルの作成のためのラットの大動脈狭窄昇順

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

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, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction4. To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential.
A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software.
Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic&#160;and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC.
Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.

Right ventricle (RV) dysfunction is critical to the pathogenesis of cardiovascular disease, yet limited methodologies are available for its evaluation. Recent advances in ultrasound imaging provide a noninvasive and accurate option for longitudinal RV study. Herein, we detail a step-by-step echocardiographic method using a murine model of RV pressure overload.

経胸壁心エコー検査による肺動脈狭窄のマウスモデルにおける右室の構造と機能の評価

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

Noninvasive Assessment of Cardiac Abnormalities in Experimental Autoimmune Myocarditis by Magnetic Resonance Microscopy Imaging in the Mouse

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events of myocardial injuries, various mouse models of myocarditis have been widely used. This study involved experimental autoimmune myocarditis (EAM) induced with cardiac myosin heavy chain (Myhc)-&#945; 334-352 in A/J mice; the affected animals develop lymphocytic myocarditis but with no apparent clinical signs. In this model, the utility of magnetic resonance microscopy (MRM) as a non-invasive modality to determine the cardiac structural and functional changes in animals immunized with Myhc-&#945; 334-352 is shown. EAM and healthy mice were imaged using a 9.4 T (400 MHz) 89 mm vertical core bore scanner equipped with a 4 cm millipede radio-frequency imaging probe and 100 G/cm triple axis gradients. Cardiac images were acquired from anesthetized animals using a gradient-echo-based cine pulse sequence, and the animals were monitored by respiration and pulse oximetry. The analysis revealed an increase in the thickness of the ventricular wall in EAM mice, with a corresponding decrease in the interior diameter of ventricles, when compared with healthy mice. The data suggest that morphological and functional changes in the inflamed hearts can be non-invasively monitored by MRM in live animals. In conclusion, MRM offers an advantage of assessing the progression and regression of myocardial injuries in diseases caused by infectious agents, as well as response to therapies.

This study demonstrates the successful establishment of magnetic resonance microscopy imaging as a non-invasive tool to assess the cardiac abnormalities in mice affected with autoimmune myocarditis. The data indicate that the technique can be used to monitor the disease-progression in live animals.

マウスでの磁気共鳴イメージング顕微鏡による実験的自己免疫性心筋炎における心臓の異常を非侵襲的に評価

Myocarditis is an inflammation of the myocardium, but only ~10% of those affected show clinical manifestations of the disease. To study the immune events ...

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.

ラットの腹部大動脈の収縮を通じて心臓リモデリングのモデル

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.

マウスにおける低侵襲横大動脈狭窄

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Echocardiographic and Histological Examination of Cardiac Morphology in the Mouse

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed in mice is high. Phenotypic characterization of these mouse models also requires the examination of cardiac function and morphology. Echocardiography and magnetic resonance imaging (MRI) are commonly used approaches to characterize cardiac function and morphology in mice. Echocardiographic and MRI equipment specialized for use in small rodents is&#160;expensive and requires a dedicated space. This protocol describes cardiac measurements in mice using a clinical echocardiographic system with a 15 MHz human vascular probe. Measurements are performed on anesthetized adult mice. At least three image sequences are recorded and analyzed for each animal in M-mode in the parasternal short-axis view. Afterwards, cardiac histological examination is performed, and cardiomyocyte diameters are determined on hematoxylin-eosin- or wheat germ agglutinin (WGA)-stained paraffin sections. Vessel density is determined morphometrically after Pecam-1 immunostaining. The protocol has been applied successfully to pharmacological studies and different genetic animal models under baseline conditions, as well as after experimental myocardial infarction by the permanent ligation of the left anterior descending coronary artery (LAD). In our experience, echocardiographic investigation is limited to anesthetized animals and is feasible in adult mice weighing at least 25 g.

Echocardiographic examination is frequently used in mice. Expensive high-resolution ultrasound devices have been developed for this purpose. This protocol describes an affordable echocardiographic procedure combined with histological morphometric analyses to determine cardiac morphology.

マウスの心臓形態の心エコー検査・組織学的検討

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed ...

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.

左室肥大の誘導マウスにおける低侵襲の横大動脈狭窄のテクニック

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.

マウスで横方向の大動脈狭窄を誘導するために閉じて胸モデル

Research on cardiac hypertrophy and heart failure is frequently based on pressure overload mouse models induced by TAC. The standard procedure is to ...

Echocardiographic Assessment of Cardiac Anatomy and Function in Adult Rats

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional imaging to study the cardiac anatomy of the left ventricle and M-mode echo to assess its dimensions. However, this could limit a comprehensive study. Herein, we describe a protocol that allows an assessment of the heart chamber size, left ventricular function (systolic and diastolic) and valvular function. A conventional medical ultrasound machine was used in this protocol and different echo views were obtained through left parasternal, apical and suprasternal windows. In the left parasternal window, the long and short axis were acquired to analyze left chamber dimensions, right ventricle and pulmonary artery dimensions, and mitral, pulmonary and aortic valve function. The apical window allows the measurement of heart chamber dimensions and evaluation of systolic and diastolic parameters. It also allows Doppler assessment with detection and quantification of heart valve disturbances (regurgitation or stenosis). Different segments and walls of the left ventricle are visualized throughout all views. Finally, the ascending aorta, aortic arch, and descending aorta can be imaged through the suprasternal window. A combination of ultrasound imaging, Doppler flow and tissue Doppler assessment have been obtained to study cardiac morphology and function. This represents an important contribution to improve the assessment of cardiac function in adult rats with impact for research using these animal models.

A non-invasive protocol for transthoracic echocardiography assessment of cardiac anatomy and function for adult rats is presented in the current study. The heart valves, all four cardiac chambers and the ascending aorta, aortic arch and descending aorta are studied in detail.

成人ラットにおける心臓解剖学と機能の心エコー評価

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional ...