1. 준비하기 1.1. 쥐의 마취 <ol><li> 쥐를 마취하기 위해 isoflurane을 (5 %의 약 3 분 챔버의 크기에 따라)로 채워져 챔버에 쥐를 놓습니다. </li><li> 일단 마취, 쥐를 제거하고 무게. </li><li> 마취를 유지하기 위해 마취 마스크 (산소 1 L / 분 isoflurane을 2-3%)에 쥐의 코를 놓습니다. isoflurane을 가진 마취 쥐의 심장 요금은 300-340 BPM (생쥐에 380-420 BPM)을 감소시킨다. </li></ol> 1.2. 꼬리 정맥 캐 뉼러를 삽입 <ol><li> 혈관이 더 쉽게 볼 수 있도록 따뜻한 물 (38 ° C), 비누와 쥐의 꼬리를 씻으십시오. </li><li> 쉽게 꼬리의 외측에서 볼 수있는 하나 정맥, Cannulate. 22-24 G IV 카테터를 사용하여 시도 약 1 / 3의 끝에서 길을 시작합니다. </li><li> 초기 노력이 실패하는 경우, 더 근위부 다시 시도하십시오. </li><li> 혈액 샘을혈소판의 분석 (세포 부피 분율 = ECV를 계산하는 데 필요한)에 대한 ple는. </li><li> 피부 접착제 및 테이프 IV 카테터를 고정합니다. </li></ol> 1.3. 전극의 위치 <ol><li> 알코올 포화 면봉이나 물과 비누로 모두 장화를 청소합니다. </li><li> 네 개의 전극은 각 발에 하나 필요합니다. </li><li> 발바닥의 중간에 전극을 부착하고 접착 테이프로 고정. </li><li> 비틀거나 ECG 신호와 간섭을 일으킬 것 루프의 형성을 최소화하기 위해 서로의 주변 ECG 케이블을 땋으. </li></ol> 2. 스캐닝 2.1. 동물과 모니터링 위치 <ol><li> 영상 튜브 위에 앙와위 또는 복와에 쥐를 놓고 코일의 중앙에 마음을 놓습니다. </li><li> 그 코 (산소 1 L / 분 2-3 %), isoflurane을 마취를 제공하는 콘에 달려도록 쥐를 정렬합니다. 쥐가 숨 허용자유롭게 전체 이미지를 만드는 절차를 통하여. </li><li> 항문 구멍에 온도계의 센서를 배치하고 테이프로 테이블에 고정합니다. </li><li> 체온은 38로 유지 ± 1 ° C 따뜻한 물 난방 시스템에 의해. 온난화 매트 코일 외부 확장 동물의 하단 부분 아래에 배치됩니다. 자세한 내용은 MRI 실험 장치 (그림 2)의 개략도를 참조하십시오. </li><li> ECG 전극을 연결 한 ECG 신호 이미징을 시작 안정적입니다. </li></ol> 2.2. 스캔 프로토콜 / 이미지 매개 변수 <ol><li> 본 연구에서는 70mm 내경 솔레노이드 코일 필립스 Ingenia 3.0T 임상 MRI 시스템은 [MR 시스템 요구 사항은 작은 구멍 (예 : 16cm) 또는 작은 동물 전용 대형 내경 (인간의 크기, 예를 들어 65cm)은 사용 된 코일, 500/min, 마취 가스에 대한 산소 공급 및 제거 시스템]을 심장 환율 ECG 게이팅 기능까지. </li><li> 보기의 MRI 필드의 중앙에 마음을 찾을 설문 조사로 시작합니다. </li><li> 위치가 정확하면, 짧은 축 이미지의 스택의 구조를 결정하는 두 개의 챔버와 네 챔버 시네 MRI보기를 계속합니다. </li><li> 두, 4 챔버 이미지 (PreSALLI)에 SALLI를 들어, 위치가 중앙 캐비티 짧은 축 조각. 4,000 밀리 취득 기간 및 4,000 밀리 초 휴식 기간의 조합은 z 축을 따라 자기의 충분한 회복을 허용하고 그라디언트의 과열을 방지합니다. 기능 분석을 활성화하려면 단계의 취득을 촉진하는 요인 2의 시간적 언더로, 최소 12으로 설정해야합니다. </li><li> 쥐를 이동하지 않고, 내재 카테터에 가돌리늄 기반 조영제를 주입. 5 분 정도 기다립니다. </li><li> 최소 7 조각 (슬라이스 두께 2.4 mm)로 구성된 multislice 짧은 축 스택으로 SALLI 계획을 시작합니다. 대부분의 말초 아래 마음과 T의 정점이되도록 조각의 위치를그는 최고 수준의 심장 밸브의 바로 원위부입니다. 짧은 축이 심장에 수직으로되어 있는지 확인하려고합니다. 거의 매 30 분 (세 SALLIs 정도) 조영제의 또 다른 복용량을 주입. </li><li> 이미지 수집이 완료되면 스캐너에서 쥐를 제거하고 마취에서 회복 할 수 있습니다. </li></ol> 3. 영상 재구성 영상 재구성은 전용 이미지 복원 도구를 사용하여 미리 정의 된 재건 매개 변수 또는 오프라인을 사용하거나 온라인으로 수행 할 수 있습니다 : 3.1. 온라인 재구성 <ol><li> 다양한 매개 변수 등을 정의 할 수 있습니다 : </li></ol><ul><li> 심장주기에서의 위치와 재건 윈도우의 폭 (예를 들어, 밀리 50 ~ 100에서 심박수 300/min에서 수축기 T1 맵을 달성하기 위해) : T1 매핑 </li><li> IR-준비 (LG 전자) 이미지 : 반전 시간의 위치와 폭 (TI) 이미지 창 수를 재구성 위스콘신 할 수가는 해당 창 (예를 들어, TI 100-300 밀리 초 5 이미지, TIS 100-150-200-250-300 밀리와 5 LG 전자의 이미지를 생성합니다.) </li></ul> 3.2. 오프라인 재구성 <ol><li> 영상 재구성을위한 전용 소프트웨어 패키지 (Gyrotools, 취리히, 스위스)를 사용하면,보다 인터랙티브 방식으로 세 세트 데이터 (시네 MR, 반전 복구 및 T1지도)를 추출합니다. </li><li> 해당 시네 이미지를 선택하여 T1에 대한 최종 수축기 또는 최종 심장 확장의 정의를 조정합니다. </li><li> 컬러 맵으로 T1 맵을 시각화. 관심 영역 위에 마우스를 전달하여 정확한 값을 찾을 수 있습니다. 이미지는 추가 분석 (사전 및 사후 대비 심근의 T1 값과 혈액 풀에서 ECV 예 : 계산) 12 다양한 이미지 형식으로 저장할 수 있습니다. </li></ol>

<ol>
	<li>Messroghli, D. R., Nordmeyer, S., Buehrer, 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=Small+animal+Look-Locker+inversion+recovery+(SALLI)+for+simultaneous+generation+of+cardiac+T1+maps+and+cine+and+inversion+recovery-prepared+images+at+high+heart+rates:+initial+experience.">Small animal Look-Locker inversion recovery (SALLI) for simultaneous generation of cardiac T1 maps and cine and inversion recovery-prepared images at high heart rates: initial experience.</a> Radiology. 261 (1), 258-2565 (2011).</li><li>Messroghli, D. R., Nordmeyer, S., Dietrich, 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=Assessment+of+diffuse+myocardial+fibrosis+in+rats+using+small-animal+Look-Locker+inversion+recovery+T1+mapping.">Assessment of diffuse myocardial fibrosis in rats using small-animal Look-Locker inversion recovery T1 mapping.</a> Circ. Cardiovasc. Imaging. 4 (6), 636-640 (2011).</li><li>Flett, A. S., Hayward, M. P., Ashworth, M. 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=Equilibrium+contrast+cardiovascular+magnetic+resonance+for+the+measurement+of+diffuse+myocardial+fibrosis:+preliminary+validation+in+humans.">Equilibrium contrast cardiovascular magnetic resonance for the measurement of diffuse myocardial fibrosis: preliminary validation in humans.</a> Circulation. 122 (2), 138-144 (2010).</li><li>Arheden, H., Saed, M., Higgins, C. 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=Measurement+of+the+distribution+volume+of+gadopentetate+dimeglumine+at+echo-planar+MR+imaging+to+quantify+myocardial+infarction:+comparison+with+99mTc-DTPA+autoradiography+in+rats.">Measurement of the distribution volume of gadopentetate dimeglumine at echo-planar MR imaging to quantify myocardial infarction: comparison with 99mTc-DTPA autoradiography in rats.</a> Radiology. 211 (3), 698-708 (1999).</li><li>Messroghli, D. R., Walters, K., Plein, 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=Myocardial+T1+mapping:+application+to+patients+with+acute+and+chronic+myocardial+infarction.">Myocardial T1 mapping: application to patients with acute and chronic myocardial infarction.</a> Magn. Reson. Med. 58 (1), 34-40 (2007).</li><li>O H-Ici, D., Ridgway, J., Kuehne, 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=Cardiovascular+magnetic+resonance+of+myocardial+edema+using+a+short+inversion+time+inversion+recovery+(STIR)+black-blood+technique:+Diagnostic+accuracy+of+visual+and+semi-quantitative.">Cardiovascular magnetic resonance of myocardial edema using a short inversion time inversion recovery (STIR) black-blood technique: Diagnostic accuracy of visual and semi-quantitative.</a> 14 (1), (2012).</li><li>Sagar, S., Liu, P. P., Cooper, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocarditis.">Myocarditis.</a> Lancet. 379, 738-747 (2012).</li><li>Skouri, H. N., Dec, G. W., Friedrich, M. G., Cooper, L. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Noninvasive+imaging+in+myocarditis.">Noninvasive imaging in myocarditis.</a> J. Am. Coll. Cardiol. , 2085-2093 (2006).</li><li>Zagrosek, A., Abdel-Aty, H., Boy&#233;, P., 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+magnetic+resonance+monitors+reversible+and+irreversible+myocardial+injury+in+myocarditis.">Cardiac magnetic resonance monitors reversible and irreversible myocardial injury in myocarditis.</a> JACC Cardiovasc. Imaging. 2 (2), 131-138 (2009).</li><li>Friedrich, M. G., Sechtem, U., Schulz-Menger, J., 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=Cardiovascular+magnetic+resonance+in+myocarditis:+a+JACC+White+Paper.">Cardiovascular magnetic resonance in myocarditis: a JACC White Paper.</a> J. Am. Coll. Cardiol. 54, 1475-1487 (2009).</li><li>Korkusuz, H., Esters, P., Naguib, 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=Acute+myocarditis+in+a+rat+model:+late+gadolinium+enhancement+with+histopathological+correlation.">Acute myocarditis in a rat model: late gadolinium enhancement with histopathological correlation.</a> Eur. Radiol. 19 (11), 2672-2678 (2009).</li><li>Ugander, M., Oki, A. J., Hsu, L. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracellular+volume+imaging+by+magnetic+resonance+imaging+provides+insights+into+overt+and+sub-clinical+myocardial+pathology.">Extracellular volume imaging by magnetic resonance imaging provides insights into overt and sub-clinical myocardial pathology.</a> Eur. Heart J. 33 (10), 1268-1278 (2012).</li><li>Gilson, W. D., Kraitchman, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+magnetic+resonance+imaging+in+small+rodents+using+clinical+1.5.">Cardiac magnetic resonance imaging in small rodents using clinical 1.5.</a> T and. 3 (1), 35-45 (2007).</li><li>Messroghli, D. R., Radjenovic, A., Kozerke, S., Higgins, D. M., Sivananthan, M. U., Ridgway, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modified+Look-Locker+inversion+recovery+(MOLLI)+for+high-resolution+T1+mapping+of+the+heart.">Modified Look-Locker inversion recovery (MOLLI) for high-resolution T1 mapping of the heart.</a> Magnetic resonance in medicine. 52 (1), 141-146 (2004).</li></ol>

모든 동물의 절차는 실험 동물의 관리 및 사용에 대한 지침에 따라 수행하고, 지역 동물 보호 당국에 의해 승인되었습니다. 관심 없음 충돌 선언하지 않습니다.

여기에서 우리는 작은 동물에서 멀티 모달 (시네 MR, 반전 복구 및 T1지도) MR 이미지를 생성하는 방법을 제시한다. 작은 동물 연구는 심혈관 질환의 연구에 점점 더 중요한 역할을하고, CMR은 우리가 심근의 기능, 구조 및 조직 구성을 연구 할 수 있도록하는 강력한 도구입니다. 그러나 작은 동물 CMR이 높은 심박수 작은 심장 크기 때문에 독특한 도전의 번호가 있습니다. 더 효율적인 방법을 포함 이?...

심근염은 급성 심장 마비, 갑작스런 죽음, 만성 확장 성 심근증 7의 주요 원인이다. CMR은 기능의 측정과 생체 조직 분석을위한 황금 표준 기술로 설립되었습니다. 새로운 이미징 기술과 영상의 개선은 심근염의 진단을 향상뿐만 아니라, 병태 생리 및 치료 표적 8-10 속도 식별의 연구를 도울 수 없습니다. 작은 동물 이미징은 심혈관 질환의 연구에 중요한 도구입니다. 같은 말 가돌리늄 향상 (LG 전자)와 같은 일상적 임상 CMR에 사용되는 기술은 쉽게 동물의 높은 심박수에 의한 작은 동물 CMR로 전송할 수 없습니다,하지만 이미 11와 같이 할 수 있습니다. 접근 방식은 멀티 모달 이미지 데이터를 생성하는 작은 동물 룩 로커 반전 회복 (SALLI)는 심장 기능과 형태를 모두 종합 평가 (그림 1을 허용하는 설정ND 3). 여기에 우리가 세부 사항, 절차 및 전형 SALLI 프로토콜과 작은 동물 이미징을위한 설정에 표시됩니다. 특히 우리는 T1 영상 데이터 세트의 재건 및 분석을 보여줍니다.

<table border="1">
		<tbody>
		 <tr>
			<td>Name of Reagent/Material</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		 </tr>
		 <tr>
			<td>Adhesive Tape (Silkafix)</td>
			<td>Lohmann und Rauscher</td>
			<td>34327</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Gadopentetat-Dimeglumin (Magnevist)</td>
			<td>Bayer</td>
			<td>G-00012163</td>
			<td>2mmol/Kg</td>
		 </tr>
		 <tr>
			<td>Introcan Safety-W (G24)</td>
			<td>B. Braun</td>
			<td>4254503-01</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Red Dot, Neonatal Monitoring Electrode with Pre-Attached Lead Wire</td>
			<td>3M</td>
			<td>2269T</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Skin glue (Histoacryl)</td>
			<td>B. Braun</td>
			<td>1050052</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Scales (Typ 440)</td>
			<td>Kern</td>
			<td>95088</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Skin desinfection (Softasept N)</td>
			<td>B. Braun Petzold</td>
			<td>360250</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Thermometer </td>
			<td>LumaSense Technologies</td>
			<td>Luxtron 812</td>
			<td></td>
		 </tr>
		</tbody>
 </table>

assessment of cardiac function and myocardial morphology using small animal look-locker inversion recovery (salli) mri in rats

작은 동물 자기 공명 영상은 심장 기능과 심근 조직의 변화를 연구하는 중요한 도구입니다. 작은 동물 (200-600 비트 / 분)의 높은 심박수는 이전 CMR 영상의 역할을 제한했다. 작은 동물 룩 로커 반전 회복 (SALLI)이 1 문제를 극복하기 위해 작은 동물을위한 T1 매핑 순서입니다. T1 맵은 조직 변경 및 조영제 속도론에 대한 정량적 인 정보를 제공합니다. 그런 간질 성 섬유증이나 부종 1-6로 확산 심근 프로세스를 탐지 할 수도 있습니다. 또한, 이미지 데이터의 단일 집합에서, 그것은 심장 기능 및 시네과 반전 복구 준비가 늦은 가돌리늄 증진 형 MR 영상 1 생성하여 흉터 심근를 검사 할 수 있습니다. 제시된 비디오 프로 시저 작은 동물 CMR 이미징을 수행하기 위해 단계별로 보여줍니다. 여기가 스프 - Dawl 건강에 관한 정보들로 안내되게됩니다어이 쥐은, 그러나 자연스럽게 서로 다른 심장 작은 동물 모델에 확장 할 수 있습니다.

여기에서 우리는 건강한 스프 돌리 쥐에서 결과를 보여줍니다. 우리가 전에 설명 잘 준비된 동물의 설치와 함께, 그것은 안정적인 ECG 신호를 얻을 수 있습니다. 인간의 심장 MRI 프로토콜과 유사하게, 우리는 마음을 찾을 수있는 설문 조사로 시작합니다. 코일 쥐의 위치가 정확한 경우에, 우리는 SALLI 스택의 형상을 감지하는 두 개의 챔버보기와 4 챔버보기를 계속합니다. SALLI ...

Watch this Scientific Journal Video about Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats at JoVE.com

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

대비 향상된 심장 자기 공명 (CMR) 영상은 포괄적 허용<em&gt; 생체 내</em&gt; 심혈관 질환의 작은 동물 모델에서 심장의 평가. 여기에 우리가 세부 절차를 CMR 영상, 재건과 쥐의 작은 동물 잠금 로커 반전 복구 (SALLI)를 사용하여 분석을 수행 할 수 있습니다.

작은 동물 룩 로커 반전 복구 (SALLI) 쥐의 MRI를 사용하여 심장 기능 및 심근 형태학의 평가

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

assessment-cardiac-function-myocardial-morphology-using-small-animal

Research

JoVE Journal

Medicine

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

12.6K 조회수.  German Heart Institute Berlin. 대비 향상된 심장 자기 공명 (CMR) 영상은 포괄적 허용 생체 내 심혈관 질환의 작은 동물 모델에서 심장의 평가. 여기에 우리가 세부 절차를 CMR 영상, 재건과 쥐의 작은 동물 잠금 로커 반전 복구 (SALLI)를 사용하여 분석을 수행 할 수 있습니다.

비디오: Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Assessment of Cardiac Function and Energetics in Isolated Mouse Hearts Using 31P NMR Spectroscopy

Bioengineered mouse models have become powerful research tools in determining causal relationships between molecular alterations and models of cardiovascular disease. Although molecular biology is necessary in identifying key changes in the signaling pathway, it is not a surrogate for functional significance. While physiology can provide answers to the question of function, combining physiology with biochemical assessment of metabolites in the intact, beating heart allows for a complete picture of cardiac function and energetics. For years, our laboratory has utilized isolated heart perfusions combined with nuclear magnetic resonance (NMR) spectroscopy to accomplish this task. Left ventricular function is assessed by Langendorff-mode isolated heart perfusions while cardiac energetics is measured by performing 31P magnetic resonance spectroscopy of the perfused hearts. With these techniques, indices of cardiac function in combination with levels of phosphocreatine and ATP can be measured simultaneously in beating hearts. Furthermore, these parameters can be monitored while physiologic or pathologic stressors are instituted. For example, ischemia/reperfusion or high workload challenge protocols can be adopted. The use of aortic banding or other models of cardiac pathology are apt as well. Regardless of the variants within the protocol, the functional and energetic significance of molecular modifications of transgenic mouse models can be adequately described, leading to new insights into the associated enzymatic and metabolic pathways. Therefore, 31P NMR spectroscopy in the isolated perfused heart is a valuable research technique in animal models of cardiovascular disease.

Assessment of Cardiac Function and Energetics in Isolated Mouse Hearts Using 31P NMR Spectroscopy

Langendorff-mode isolated heart perfusion, in conjunction with 31P NMR spectroscopy, combines the fields of biochemistry and physiology into one experiment. The protocol allows for the dynamic measurement of high energy phosphate content and turnover in the heart while concurrently monitoring physiologic function. When performed correctly, this is a valuable technique in the assessment of cardiac energetics.

를 사용하여 절연 마우스 마음에 심장 기능 및 에너 지학 평가 31 P NMR 분광학

Bioengineered mouse models have become powerful research tools in determining causal relationships between molecular alterations and models of ...

연구

의학

Acute Myocardial Infarction in Rats

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial infarction (AMI). This model is also referred to as an acute ischemic cardiomyopathy or ischemia followed by reperfusion (IR); which is induced by an acute 30-minute period of ischemia by ligation of the left anterior descending artery (LAD) followed by reperfusion of the tissue by releasing the LAD ligation (Vasilyev and McConnell). This protocol will focus on assessment of the infarct size and the area-at-risk (AAR) by Evan's blue dye and triphenyl tetrazolium chloride (TTC) following 4-hours of reperfusion; additional comments toward the evaluation of cardiac function and remodeling by modifying the duration of reperfusion, is also presented. Overall, this AMI rat animal model is useful for studying the consequence of a myocardial infarction on cardiac pathophysiological and physiological function.

The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.

고양이에서 급성 심근 경색

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular ...

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

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.

압력 과부하 심장 비대 모델의 창조를위한 쥐의 대동맥 수축 오름차순

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.

경 흉부 심 초음파에 의한 폐동맥 수축의 마우스 모델에서 마우스 오른쪽 심실 구조 및 기능의 평가

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

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.

마우스의 심장 형태학의 echocardiographic 및 조직학 검사

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

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The amount of the different tissues in the callus provides important information on the fracture healing progress. Available in vivo techniques to longitudinally monitor the callus tissue development in preclinical fracture-healing studies using small animals include digital radiography and &#181;CT imaging. However, both techniques are only able to distinguish between mineralized and non-mineralized tissue. Consequently, it is impossible to discriminate cartilage from fibrous tissue. In contrast, magnetic resonance imaging (MRI) visualizes anatomical structures based on their water content and might therefore be able to noninvasively identify soft tissue and cartilage in the fracture callus. Here, we report the use of an MRI-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice. The experiments demonstrated that the fixator and a custom-made mounting device allow repetitive MRI scans, thus enabling longitudinal analysis of fracture-callus tissue development.

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

The evaluation of tissue development in the fracture callus during endochondral bone healing is essential to monitor the healing process. Here, we report the use of a magnetic resonance imaging (MRI)-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in mice.

Vivo에서 골절 뼈 쥐 마우스 대 퇴 골에 대 한 MRI-호환 Osteosynthesis 장치를 사용 하 여 치료 기간 동안 굳은 살 개발의 평가

Endochondral fracture healing is a complex process involving the development of fibrous, cartilaginous, and osseous tissue in the fracture callus. The ...

Normothermic Ex Situ Heart Perfusion in Working Mode: Assessment of Cardiac Function and Metabolism

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation time and increases the risk of adverse post-transplantation outcomes. Moreover, the static nature of CS does not allow for organ evaluation or intervention during the preservation interval. Normothermic ex situ heart perfusion (ESHP) is a novel method for preservation of the donated heart that minimizes cold ischemia by providing oxygenated, nutrient-rich perfusate to the heart. ESHP has been shown to be non-inferior to CS in the preservation of standard-criteria donor hearts and has also facilitated the clinical transplantation of the hearts donated after the circulatory determination of death. Currently, the only available clinical ESHP device perfuses the heart in an unloaded, non-working state, limiting assessments of myocardial performance. Conversely, ESHP in working mode provides the opportunity for comprehensive evaluation of cardiac performance by assessment of functional and metabolic parameters under physiologic conditions. Moreover, earlier experimental studies have suggested that ESHP in working mode may result in improved functional preservation. Here, we describe the protocol for ex situ perfusion of the heart in a large mammal (porcine) model, which is reproducible for different animal models and heart sizes. The software program in this ESHP apparatus allows for real-time and automated control of the pump speed to maintain desired aortic and left atrial pressure and evaluates a variety of functional and electrophysiological parameters with minimal need for supervision/manipulation.

Normothermic ex situ heart perfusion (ESHP), preserves the heart in a beating, semi-physiologic state. When performed in a working mode, ESHP provides the opportunity to perform sophisticated assessments of donor heart function and organ viability. Here, we describe our method for myocardial performance evaluation during ESHP.

작업 모드에 Situ 심장 관류 Ex normothermic: 심장 기능 및 대사 평가

The current standard method for organ preservation (cold storage, CS), exposes the heart to a period of cold ischemia that limits the safe preservation ...

Continuous Blood Sampling in Small Animal Positron Emission Tomography/Computed Tomography Enables the Measurement of the Arterial Input Function

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal blood time-activity concentration also known as arterial input function (AIF) is a key point, especially for the characterization of animal disease models and the introduction of newly developed radiotracers. The knowledge of radiotracer availability in the blood helps to interpret PET/CT-derived data of tissue activity. For this purpose, online blood sampling during the PET/CT imaging is advisable to measure the AIF. In contrast to manual blood sampling and image-derived approaches, continuous online blood sampling has several advantages. Besides the minimized blood loss, there is an improved resolution and a superior accuracy for the blood activity measurement. However, the major drawback of online blood sampling is the costly and time-consuming preparation to catheterize the femoral vessels of the animal. Here, we describe an easy and complete workflow for catheterization and continuous blood sampling during small animal PET/CT imaging and compared it to manual blood sampling and an image-derived approach. Using this highly-standardized workflow, the determination of the fluorodeoxyglucose ([18F]FDG) AIF is demonstrated. Further, this procedure can be applied to any radiotracer in combination with different animal models to create fundamental knowledge of tracer kinetic and model characteristics. This allows a more precise evaluation of the behavior of pharmaceuticals, both for diagnostic and therapeutic approaches in the preclinical research of oncological, neurodegenerative and myocardial diseases.

Here a protocol for continuous blood sampling during PET/CT imaging of rats to measure the arterial input function (AIF) is described. The catheterization, the calibration and setup of the system and the data analysis of the blood radioactivity are demonstrated. The generated data provide input parameters for subsequent bio-kinetic modeling.

작은 동물 양전자 방출 단층 촬영 / 컴퓨터 단층 촬영에서 지속적인 혈액 샘플링은 동맥 입력 기능의 측정을 가능하게

For quantitative analysis and bio-kinetic modeling of positron emission tomography/computed tomography (PET/CT) data, the determination of the temporal ...

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.

성인 쥐에서 심장 해부학 및 기능의 심초음파 평가

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