Name: histological quantification of chronic myocardial infarct in rats
Uploaded: 2016-12-11T14:00:00.000+00:00
Duration: 9 min 45 s
Description: Watch this Scientific Journal Video about Histological Quantification of Chronic Myocardial Infarct in Rats at JoVE.com

The study was supported by the Swiss National Foundation [SNF 310030-149986 to MNG], the University of Fribourg, and Fribourg Hospital.

Tüm hayvanlar Hayvan Bakım Dair Avrupa Sözleşmesi uyarınca insancıl bakıma aldı. Cerrahi işlemler İsviçre Federal Veterinerlik Dairesi, İsviçre tarafından onaylanan Devlet Veterinerlik Ofisi, Fribourg, izin aldıktan sonra İsviçre Hayvanları Koruma Kanunu uyarınca yapıldı. 1. Kalp Hasat NOT: Tüm cerrahi girişimler izofluran anestezi altında yapıldı. Çabaları hayvan acı azaltmak için yapılmıştır. Özel olarak, bütün hayvanlar 0.1 mg / kg buprenorfin ön anestezi deri altı enjeksiyonu yapıldı. Miyokard enfarktüsü inducting için cerrahi protokol daha önce başka bir yerde 13 tarif edilmiştir. <ol><li> Anestezi (entübe hayvan,% 2,5 izofluran, pençe tutam refleks ile teyit uygun anestezi) altında myocardially enfarkte hayvan üzerinde bir sternotomi gerçekleştirin. <ol><li> Daha sonra kasları cilt kesme ve hayvansal açıncerrahi makas ile. sol ve sağ kaburga kesin ve ardından göğüs çıkarın. </li><li> Bir önceki ameliyatı (LAD ligasyonu) sonra kalan yapışıklıklar çıkarın. aort kesin ve kalp kaldırmak. (PBS içinde) 1 M KCl doku yerleştirin ve daha sonra PBS ile yıkayın. </li></ol></li></ol> 2. Doku Hazırlanması <ol><li> akrilik sıçan kalp matris içinde uzunlamasına infarkt kalbi koyun. 1 saat boyunca -20 ° C&#39;de saklayın. </li><li> Bir çapraz olan bir traş makinesi bıçak kullanılarak matris içinde doğrudan kalp kesin. Her dilim sağlamak 2 mm kalınlığında. (Remodeling seviyesine göre) her kalp için 7 slaytlar - yaklaşık 5 Cut Bu sistematik örnekleme denir. </li><li> Bu aşamada, 2,3,5-triphenyltetrazolium klorür (TTC) boyama performans (kalp dilimleri tabanına-to-apeks yönünü tutmak) isteğe bağlıdır. <ol><li> 37 ° C&#39;de 50 dakika boyunca PBS içinde% 1 TTC inkübe edin. 1 saat 20 dakika süreyle% 4 paraformaldehid (PFA) içinde inkübe edin. betwee bölümleri koymakn 2 mm pullarla iki cam plakalar ve 15X büyütmede bir kamera ile birleştiğinde stereolojik mikroskobu ile fotoğraf çekmek. DİKKAT! Paraformaldehit toksiktir. </li></ol></li><li> Slayt dondurma (1. seçenek) <ol><li> (Kalıbın alt aşağı bölümün apeks odaklı tarafını yerleştirin) yönünü korumak cryotomy için orta (optimum kesme sıcaklığı, OKT) montaj bir plastik kalıp (10 x 10 x 5 mm) her slayt koyun. 15 dakika - 10 soğutma sıvı azot altında 2-metilbütan buharları ile blokları dondurun. Son olarak, -80 ° C de doku saklayın. </li></ol></li><li> Paraffinization (2. isteğe bağlı) <ol><li> 24 saat süreyle% 4 PFA sonra her kasetleri gömme slayt (aşağı kasetin altındaki bölümünün apeks odaklı yan koyarak yönünü korumak) ve yerleştirin. Bir doku işlemci makine gecede koy. <ol><li> 2 saat boyunca, etanol% 70 içinde inkübe edin. Ethan içinde inkübe2 saat boyunca 95% ol. 3 saat% 100 etanol içinde inkübe edin. 4 saat ksilol içinde inkübe edin. 5 saat (bir fırın içinde 60 ° C &#39;de erimiş) parafin içinde inkübe edin. Son olarak, parafin her kalp slayt gömerek blok yapmak. </li></ol></li></ol></li></ol> 3. Masson-Goldner Trikrom Boyası <ol><li> (: 5 mikron kalınlığında) ya da -18 ° C&#39;ye ayarlanmış bir kriyostat ile Ekim bloklardan (kalınlığı: 7 mikron) manuel mikrotom ile parafin bloklardan doku bölümleri yapın. </li><li> Masson-Goldner ile - (slayt başına 4 enine kesitleri 3) trikrom boyama (bkz) her sıçan için her kalp kısmından bir slayt Leke. NOT: parafin kesitler için bu adımdan başlayın. <ol><li> bir fırın içinde 60 ° C &#39;de slaytlar eritin. davlumbaz altında, 10 dakika her biri için iki kez ksilol onları deparaffinize. 3 dakika her biri için% 100 etanol,% 95 etanol,% 70 etanol ve distile suda rehidrate. Not: cryosection bu aşama Başlangıçs. </li><li> Bouin çözümü gecede bunları düzeltmek. 15 dakika - Sonra, 10 musluk suyu ile durulayın. damıtılmış su içinde çalkalanır. 3 dakika boyunca Mayer hematoksilin bunları inkübe edin. </li><li> slaytları çıkarın ve 5 dakika için damıtılmış su içinde bırakın. Daha sonra, 5 dakika boyunca asit Fuchsin-Ponceau bunları inkübe edin. 1 dakika için% 1 asetik asit ile durulayın. </li><li> Daha sonra, 1 dakika için fosfomolibdik asit Orange G inkübe. 1 dakika süre ile% 1 asetik asit ile durulayın, 10 dakika boyunca hafif bir yeşil boya bunları tasarlamak ve 1 dakika süre ile% 1 asetik asit içinde çalkalanır. </li><li> % 70 etanol (30 sn),% 95 etanol (30 sn), ve% 100 etanol (5 dakika) bunları kurutmak. , Doku kesitlerinde bir reçineli montaj orta bir damla koymak lamelleri ile onları karşılamak ve kurumaya bırakın. </li></ol></li></ol> 4. Enfarktüs Boyut Analizi <ol><li> Bir kamera ile birleştiğinde bir stereomikroskopta (15X büyütme) her slayttan bir görüntü kazanır. Aynı ayarıyla bir cetvel fotoğrafs. </li><li> enfarktüs, septum kalınlığı, sol ventrikül (LV) oyuğu alanı, infarkt alanı ve kullanma LV doku alanının ortasında skar kalınlığını ölçmek için görüntü analiz yazılımı kullanın. <ol><li> Cetvel resmi (Şekil 1A) ile ölçeği ayarlayın. <ol><li> Daha sonra Set Dönüşüm Faktörü seçin Ölçümleri tıklayın. Kalibrasyon çubuğunda bir çizgi çizin. Sağ resmin üzerine tıklayın ve Bitiş kalibrasyon tıklayın. Bar değerini not alın ve sonra Tamam &#39;ı tıklatın. </li></ol></li><li> Lekeli kalp resmi (Şekil 1B) den LV seçin. Birden bölüm aracını kullanın. LV noktası-by-point seçin ve ardından sağ tıklayın Kopyala / Yapıştır her yerde. </li><li> Tek parça ölçüm aracını kullanarak skar ve septum kalınlığı ölçmek (Şekil 1C </stRong&gt;). </li><li> Otomatik LV boşluğu, infarkt tespit ve LV alanları RGB modunda (Şekil 1D) otomatik alan ölçümü aracını kullanarak. <ol><li> aracını tıklayın. Etkinleştirin Sadece Sınırlar ve RGB modunda bitişik. Son olarak, bunu tespit etmek ilgi alanı içinde tıklatın. Gerekirse, hassas aletler kullanın. </li></ol></li></ol></li><li> AG alanına infarkt alanı oranı olarak enfarktüs boyutunu hesaplayın. </li><li> aşağıdaki gibi genişleme endeksi hesaplayın: [LV boşluğu alanı / bütün LV alanı] / [enfarktüs kalınlığı / septum kalınlığı], LV boşluğu ve LV doku alanlarında hem dahil bütün LV alanı ile. </li><li> Sonunda şöyle, her kalp için bir &quot;ortalama&quot; hesaplamak: [infarkt slaytlar genişleme endeksinin ortalama] * [infarkt slaytlar sayısı slaytlar / toplam sayısı]. </li></ol>

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The authors have nothing to disclose.

Protokol çerçevesinde kritik adımlar Fibrotik doku doğru hasat kalp ve görüntünün sistematik örnekleme yöntemiyle kronik MI sıçan modelinde değerlendirilebilir tabandan tepeye doğru edilen trichromatic lekeli histolojik kesitlerin analiz eder. Iki adım başarılı protokol uygulanması için özellikle önemlidir. İlk olarak, kalp hasat için KCI kullanımı kalp kası rahat bir halde muhafaza edilmesini sağlar. Bu aşama, farklı kalplerinden infarkt boyutl...

Miyokard infarktüsü (Mİ) dünya çapında ölüm ve sakatlık önde gelen nedenidir. Koroner kalp hastalığı ana nedenidir; MI böyle tıkanıklığı koroner olaylara ardışık iskemi kaynaklanır. reperfüzyon ilk 6 saat içinde gerçekleştirilen olmadığında, iskemi geri dönüşü olmayan miyokard nekrozu neden olur. Hastalarda, MI karakterizasyonu klinik bulgular, elektrokardiyografi, biyomarkerlerin, ekokardiyografi, MR görüntüleme plazma seviyelerinin değerlendirilmesi dahil olmak üzere farklı tanı araçları, dayanır ve histolojik 1 analizleri. Akut ve kronik MI koroner oklüzyon zaman miyokard nekrozu göreli zamanlamasına göre yaralanma iki farklı aşamalarında olarak sınıflandırılır. ilk 7 günü içinde ortaya çıkan akut faz, kardiyomiyositlerin kaybı, detaylı enflamasyon ve fibroblastların alımı ile ilişkilidir. kardiyak doku ve bir yara oluşması iyileşmesi ile karakterize edilen bir alt-akut faz, meydana1 ila 4-6 haftadır. enfarktüs, ventrikül duvar incelmesi ve ventrikül dilatasyon Genişleme kronik faz karakterize eder. Sol ventrikül geniş biçimlenme giderek şiddetli kalp yetmezliği 2 sonuçlanır. Kalıcı sol ön inen arter (LAD) ligasyonu ile uyarılan MI kronik miyokard infarktüsü standart kemirgen modeli temsil eder. Koroner bağ taklit koroner oklüzyon. infarkt büyüklüğü ligasyonu sitede bağlıdır. Bir kemirgen modelinde miyokard iskemik hasar Karakterizasyonu klasik gibi troponin olarak biyobelirteç plazma seviyelerini, kullanılarak yapılır I ve T 3, ekokardiyografi, MR ve histoloji 4,5. Biyomarker seviyeleri Kardiyomiyosit ölüm yaygınlığı ile ilişkilidir. Ekokardiyografi, bölgesel duvar hareket bozukluğu kaynaklanan sol ventrikül fonksiyon bozukluğu değerlendirir. MRI veya yüksek çözünürlüklü olarak eklenmesi, non-invaziv görüntüleme teknikleri, içindeekokardiyografi, duvar hareketi azalma değerlendirilmesine olanak azaltılmış perfüzyon ve canlı miyokard ve duvar incelme ile yara alanının hacmi. LV boyutları infarkt doğru değerlendirilmesine izin verir. Son olarak, canlı ve ölü miyokardın miktar hasat kalplerin histolojik bölümlerde özel boyalar kullanılarak otopsi yapılmış ve enfarktüs boyutunu (IS) doğrulanmasını sağlar edilebilir. Bir diğer önemli özelliği enfarktüs genişleme indeksi (EI) 6 değerlendirilmesidir. EI ilk 3 gün içinde transmural enfarktüs ve başlar ilişkilidir. EI duvar kalınlığı artan bir şekildeki azalma, sol ventrikül boşluğu boyutunda bir artış ve AG şeklinde buna bağlı olarak değişiklikler ile karakterizedir. yeni tedavilerin terapötik etkinliğini değerlendirmek için - özellikle rejeneratif stratejiler hücreler, matrisler dayalı ve kemirgenlerde MI gen teslimi-doğru bir değerlendirme büyük önem taşımaktadır.papiller kas düzeyinde elde edilen tek bir kesitte ölçülen zaman, IS boyutu LAD ligasyon aşağıdaki enfarktüs gelişme var büyük değişkenlik nedeniyle önyargılı olabilir; tepe infarkt sonra occulted olabilir. Önemli olarak, tespit MI boyutuna daha doğru metodolojiler fareler 7-9 ya da sıçanlar 10 için tarif edilmiştir. Bununla birlikte, IS doğru LV biçimlenme ya da yeniden terapötik uyarılan azalmalar (veya önleme yollarını) ölçmek için yeterli değildir. Gerçekten de, genel olarak kalbin kesitleri üzerinde belirlenen toplam LV hacminin bir yüzdesi olarak ifade edilir. Bu yöntem, akut MI için geçerli olmasına karşın, yeniden sırasında meydana gelen AG duvarının incelmesi 11,12 değerlendirdi altında kalır. infarkt ve yapısal değişikliklerin tam bir morfometrik ölçümü gibi endokardiyal ve epikardiyal uzunluk ve çaplarda yanı sıra enfarktüs ve sağlıklı alanlar gibi çeşitli parametreler, ölçmek gerekir. Biz bir metodolojik yakl tarifoach doğru kronik sıçan modelinde MI ve yenileme değerlendirmek.

<table><tbody><tr><td>Acrylic rat heart matrix 2 mm</td><td>72-5015</td><td>Harvard Appartus</td><td></td></tr><tr><td>Inspira advanced volume controlled ventilator</td><td>Harvard Apparatus</td><td>557058</td><td></td></tr><tr><td>Catheter Insyte 14 G</td><td>BD</td><td>381267</td><td></td></tr><tr><td>O.C.T</td><td>BDHA361603E</td><td>VWR</td><td></td></tr><tr><td>TTC</td><td>T8877-10G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Mayer hematoxylin</td><td>MHS32-1L</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Acid Fuchsin&lt;br/&gt; CI 42685</td><td>F8129-50G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Ponceau Xylidin&lt;br/&gt; CI 16150</td><td>P2395-25G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Orange G&lt;br/&gt; CI 16230</td><td>O3756-100G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Light green&lt;br/&gt; CI 42095</td><td>L5382-25G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>KCl</td><td>P9333-500G</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Xylol</td><td>10315083</td><td>HoneyWell</td><td></td></tr><tr><td>Ethanol absolute</td><td>10303990</td><td>HoneyWell</td><td></td></tr><tr><td>2-methylbutane</td><td>M32631-1L</td><td>Sigma Aldrich</td><td></td></tr><tr><td>Stereogical microscope</td><td>SM2800</td><td>Nikon</td><td></td></tr><tr><td>Formaldehyde</td><td>99340</td><td>Reactolab</td><td></td></tr><tr><td>Embedding cassette</td><td>K113.1</td><td>Carl Roth</td><td></td></tr><tr><td>Bersoft Image measurement Software</td><td></td><td>Bersoft.com</td><td>Licensed software</td></tr></tbody></table>

histological quantification of chronic myocardial infarct in rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ischemic injury. Following the initial acute phase, chronic remodeling of the left ventricle (LV) modifies the structure and function of the heart. Permanent coronary ligation in small animals has been widely used as a reference model for a chronic model of MI. Thinning of the infarcted wall progressively develops to transmural fibrosis. Histological assessment of infarct size is commonly performed; nevertheless, a standardization of the methods for quantification is missing. Indeed, important methodological aspects, such as the number of sections analyzed and the sampling and quantification methods, are usually not described and therefore preclude comparison across investigations. Too often, quantification is performed on a single section obtained at the level of the papillary muscles. Because novel strategies aimed at reducing infarct expansion and remodeling are under investigation, there is an important need for the standardization of accurate heart sampling protocols. We describe an accurate method to quantify the infarct size using a systematic sampling of harvested rat heart and image analyses of trichromatic stained histological sections obtained from base to apex. We also provide evidence that calculating the expansion index (EI) allowed for infarct size assessment, taking into account changes of the left ventricle throughout the remodeling.

Altı hafta sonra, LAD ligasyonu, kalpler Lewis sıçanlarında hasat edildi. 2 mm doku kesitleri tepesinden tabanına elde edilmiştir. Bir TTC boyama işlemi beyaz görünen infarkt alanı, ve kırmızı görünen sağlıklı miyokard, (Şekil 2) görselleştirmek için yapıldı. LAD ligasyonu sitede bağlı olarak, enfarktüs boyutu değişir. Büyük MI için transmural infarktlar taban (Şekil 2A) için tepesinden gözlendi. Daha küçük infarktla...

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Histological Quantification of Chronic Myocardial Infarct in Rats

The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

Sıçanlar Kronik Kalp Enfarktüsü histolojik Niceleme

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ...

histological-quantification-of-chronic-myocardial-infarct-in-rats

Universidad de Cartagena UDEC

Research

JoVE Journal

Medicine

14.5K Görüntüleme.  University of Fribourg. The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections. 

Video: Histological Quantification of Chronic Myocardial Infarct in Rats

Coronary Artery Ligation and Intramyocardial Injection in a Murine Model of Infarction

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo. With the advent of genetic modifications to the whole organism or the myocardium and an array of biological and/or synthetic materials, there is great potential for any combination of these to assuage the extent of acute ischemic injury and impede the onset of heart failure pursuant to myocardial remodeling. 
Here we present the methods and materials used to reliably perform this microsurgery and the modifications involved for temporary (with reperfusion) or permanent coronary artery occlusion studies as well as intramyocardial injections. The effects on the heart that can be seen during the procedure and at the termination of the experiment in addition to histological evaluation will verify efficacy. 
Briefly, surgical preparation involves anesthetizing the mice, removing the fur on the chest, and then disinfecting the surgical area. Intratracheal intubation is achieved by transesophageal illumination using a fiber optic light. The tubing is then connected to a ventilator. An incision made on the chest exposes the pectoral muscles which will be cut to view the ribs. For ischemia/reperfusion studies, a 1 cm piece of PE tubing placed over the heart is used to tie the ligature to so that occlusion/reperfusion can be customized. For intramyocardial injections, a Hamilton syringe with sterile 30gauge beveled needle is used. When the myocardial manipulations are complete, the rib cage, the pectoral muscles, and the skin are closed sequentially. Line block analgesia is effected by 0.25% marcaine in sterile saline which is applied to muscle layer prior to closure of the skin. The mice are given a subcutaneous injection of saline and placed in a warming chamber until they are sternally recumbent. They are then returned to the vivarium and housed under standard conditions until the time of tissue collection. At the time of sacrifice, the mice are anesthetized, the heart is arrested in diastole with KCl or BDM, rinsed with saline, and immersed in fixative. Subsequently, routine procedures for processing, embedding, sectioning, and histological staining are performed. 
Nonsurgical intubation of a mouse and the microsurgical manipulations described make this a technically challenging model to learn and achieve reproducibility. These procedures, combined with the difficulty in performing consistent manipulations of the ligature for timed occlusion(s) and reperfusion or intramyocardial injections, can also affect the survival rate so optimization and consistency are critical.

Numerous genetic manipulations and/or intramyocardial injections of genes, proteins, cells, and/or biomaterials are superimposed upon the dimension of time in studies of acute ischemia/ reperfusion injury and chronic remodeling in mice. This video illustrates the microsurgical procedures for ischemia/reperfusion, permanent coronary artery ligation, and intramyocardial injection studies.

Enfarktüsü bir murin Model Koroner Arter ligasyon ve intramiyokardiyal Enjeksiyon

Mouse models are a valuable tool for studying acute injury and chronic remodeling of the myocardium in vivo.  With the advent of genetic modifications to ...

Tıp

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD).

In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

This method outlines the use of Quantum Micro-Computed Tomography (MicroCT) to assess cardiac morphology, function, perfusion, metabolism and viability with iodinated contrast agent in mice with experimentally-induced myocardial ischemia. The technique can be applied for non-destructive high-throughput longitudinal in vivo imaging of various animal models of human heart disease.

Miyokard Yapı, Fonksiyon Vivo Kantitatif Değerlendirilmesi yılında Perfüzyon ve Canlılık Kardiyak Mikro-bilgisayarlı Tomografi ile

The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that ...

Biyomühendislik

Minimal Invasive Surgical Procedure of Inducing Myocardial Infarction in Mice

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last decades. For clarification of the underlying mechanisms and the development of new therapeutic strategies, the availability of valid animal models are mandatory. Since we need new insights into pathomechanisms of cardiovascular diseases under in vivo conditions to combat myocardial infarction, the validity of the animal model is a crucial aspect. However, protection of animals are highly relevant in this context. Therefore, we establish a minimally invasive and simple model of myocardial infarction in mice, which assures a high reproducibility and survival rate of animals. Thus, this models fulfils the requirements of the 3R principle (Replacement, Refinement and Reduction) for animal experiments and assure the scientific information needed for further developing of therapeutical strategies for cardiovascular diseases.

A highly reproducible model for myocardial infarction in mice with minimal invasive manipulations is described. The model can be easily performed, resulting in a high reproducibility and survival rate. Thus, the described model will reduce the number of required animals as requested by the 3R principle (Replacement, Refinement and Reduction).

Farelerde Miyokard İnfarktüsü Oluşturan Minimal İnvaziv Cerrahi Prosedür

Myocardial infarction still remains the main cause of death in western countries, despite considerable progress in the stent development area in the last ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

Akut Miyokard İnfarktüsü bir Domuz Modeli İlköğretim Sonuç Değerlendirmesi

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine models of MI with permanent ligation of left-anterior descending (LAD) coronary artery closely mimics MI in humans. Murine models benefit from the extensive genetic engineering available nowadays. Here we propose a reproducible murine surgical model of myocardial infarction by permanent LAD coronary ligation. Our technique comprises anesthesia with ketamine/xylazine that can be rapidly reversed by administration of an antagonist, intubation without tracheotomy for mechanical-assisted ventilation, ventilation with application of extrinsic positive end-expiratory pressure (PEEP) to avoid alveolar collapse, a thoracotomy method limiting to the minimum surgical lesions made to skeletal muscles, and lung inflation without thoracentesis. This method is sparsely invasive, reproducible and reduces post-surgery mortality and complications.

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological processes.

Sol Anterior İnen Koroner Arterin Kalıcı Ligasyonu ile Murine Miyokard Enfarktüsü Modeli

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine ...

A New Model of Heart Failure Post-Myocardial Infarction in the Rat

Ligation of the left anterior descending (LAD) coronary artery has been widely used to establish the rat model of heart failure (HF) post myocardial infarction (MI). However, the disadvantages of this model include high mortality rate after ligation and larger variations both in the infarct size and the degree of impaired cardiac function. In addition, a ventilator or exteriorization of the heart is indispensable for the previous models, which complicates the procedure during the ligation. In this study, we developed a reliable and reproducible model without the ventilator or exteriorization of the heart by ligating the LAD coronary artery. Four weeks after the procedure, we found that the serum concentrations of CK-MB, NT-proBNP, and Renin, which were used to assist diagnoses of MI and HF, were significantly higher in the MI group compared to the sham group. In contrast, the value of left ventricle ejection fraction (LVEF) in the MI group was obviously less than in the sham group. Furthermore, the infarct size and cardiac fibrosis area were individually confirmed and quantitatively analyzed by TTC staining and Masson's trichrome staining. Smaller variations were found in either infarct size or fibrosis area in the MI group, which helped to develop a reliable and reproducible model of HF post-MI. This new model of HF post-MI in the rat is vital for studying the potential mechanisms of MI and HF. This new method can be used to develop the new drug for treatment of MI and HF in rats by using pharmacological strategies.

We successfully developed a reliable and reproducible model of heart failure post-myocardial infarction in the rat without ventilation or exteriorization of the heart. This simplifies the procedure and benefits the further studies about the potential mechanisms behind the heart failure.

Ligation of the left anterior descending (LAD) coronary artery has been widely used to establish the rat model of heart failure (HF) post myocardial ...

An Intact Pericardium Ischemic Rodent Model

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to induce myocardial injury). The majority of pre-clinical myocardial infarction models require the disruption of pericardial integrity with loss of the homeostatic cellular milieu. However, recently a methodology has been developed by us to induce myocardial infarction, which minimizes pericardial damage and retains the heart&#39;s resident immune cell population. An improved cardiac functional recovery in mice with an intact pericardial space following coronary ligation has been observed. This method provides an opportunity to study inflammatory responses in the pericardial space following myocardial infarction. Further development of the labeling techniques can be combined with this model to understand the fate and function of pericardial immune cells in regulating the inflammatory mechanisms that drive remodeling in the heart, including fibrosis.

This protocol outlines the steps for inducing myocardial infarction in mice while preserving the pericardium and its contents.

Bozulmamış Bir Perikard İskemik Kemirgen Modeli

This protocol has shown that the pericardium and its contents play an essential anti-fibrotic role in the ischemic rodent model (coronary ligation to ...

Generation and Characterization of Right Ventricular Myocardial Infarction Induced by Permanent Ligation of the Right Coronary Artery in Mice

Right ventricular infarction (RVI) is a common presentation in clinical practice. Severe RVI can lead to fatal hemodynamic dysfunction and arrhythmia. In contrast to the extensively used mouse myocardial infarction (MI) model generated by left coronary artery ligation, the RVI mouse model is rarely employed due to the difficulty associated with model generation. Research on the mechanisms and treatment of RVI-induced RV remodeling and dysfunction requires animal models to mimic the pathophysiology of RVI in patients. This study introduces a feasible procedure for RVI model generation in C57BL/6J mice. Further, this model was characterized based on the following: infarct size evaluation at 24 h after MI, assessment of cardiac remodeling and function with echocardiography, RV hemodynamics assessment, and histology of the infarct zone at 4 weeks after RVI. In addition, a coronary vasculature cast was performed to observe the coronary arterial arrangement in RV. This mouse model of RVI would facilitate the research on mechanisms of right heart failure and seek new therapeutic targets of RV remodeling.

There are several differences between the right and left ventricles. However, the pathophysiology of right ventricular infarction (RVI) has not been clarified. In the present protocol, a reproducible method for RVI mouse model generation is introduced, which may provide a means to explain the mechanism of RVI.

Farelerde Sağ Koroner Arterin Kalıcı Ligasyonu ile İndüklenen Sağ Ventrikül Miyokard İnfarktüsünün Oluşumu ve Karakterizasyonu

Right ventricular infarction (RVI) is a common presentation in clinical practice. Severe RVI can lead to fatal hemodynamic dysfunction and arrhythmia. In ...

Ultrasound-Guided Induced Pluripotent Stem Cell-Derived Cardiomyocyte Implantation in Myocardial Infarcted Mice

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are a promising cell source for cardiac repair after ischemic damage. However, a low grafted rate is a significant obstacle for effective cardiac tissue regeneration after transplantation. This protocol shows that multiple hiPSC-CM ultrasound-guided percutaneous injections into an MI area effectively increase cell transplantation rates. The study also describes the entire hiPSC-CM culture process, pretreatment, and ultrasound-guided percutaneous delivery methods. In addition, the use of human mitochondrial DNA help detect the absence of hiPSC-CMs in other mouse organs. Lastly, this paper describes the changes in cardiac function, angiogenesis, cell size, and apoptosis at the infarcted border zone in mice 4 weeks after cell delivery. It can be concluded that echocardiography-guided percutaneous injection of the left ventricular myocardium is a feasible, relatively invasive, satisfactory, repeatable, and effective cellular therapy.

Ultrasound-guided cell delivery around the site of myocardial infarction in mice is a safe, effective, and convenient way of cell transplantation.

Miyokard Enfarktüslü Farelerde Ultrason Rehberliğinde İndüklenen Pluripotent Kök Hücre Kaynaklı Kardiyomiyosit İmplantasyonu

The key objective of cell therapy after myocardial infarction (MI) is to effectively enhance the cell grafted rate, and human induced pluripotent stem ...

An Experimental Model of Myocardial Infarction for Studying Cardiac Repair and Remodeling in Knockout Mice

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. This paper describes a protocol for studying the role of galectin 3 (Gal-3) in the temporal evolution of cardiac healing and remodeling in an experimental animal model of MI. 
The procedures described include an experimental model of MI with a permanent coronary ligature in male C57BL/6J (control) and Gal-3 knockout (KO) mice, an echocardiography procedure to study cardiac remodeling and systolic function in vivo, a histological evaluation of interstitial myocardial fibrosis with picrosirius red-stained and rhodamine-conjugated lectin-stained sections for studying myocyte hypertrophy by the cross-sectional area (MCSA), and the quantification of infarct size and cardiac remodeling (scar thinning, septum thickness, and expansion index) by planimetry in slices stained with Masson's trichrome and triphenyl tetrazolium chloride. Gal-3 KO mice with MI showed disrupted cardiac remodeling and an increase in the scar thinning ratio and the expansion index. At the onset of MI, myocardial function and cardiac remodeling were also severely affected. At 4 weeks post MI, the natural evolution of fibrosis in infarcted Gal-3 KO mice was also affected. 
In summary, the experimental model of MI is a suitable model for studying the temporal evolution of cardiac repair and remodeling in mice with the genetic deletion of Gal-3 and other animal models. The lack of Gal-3 affects the dynamics of cardiac repair and disrupts the evolution of cardiac remodeling and function after MI.

Here, we describe an experimental model of myocardial infarction, an echocardiography procedure to study cardiac remodeling and function, and procedures for quantifying fibrosis and hypertrophy in picrosirius red-stained and rhodamine-stained sections, as well as the infarct size and expansion index in slices stained with Masson's trichrome.

Cardiovascular disease is the most prevalent cause of death in Western countries, with acute myocardial infarction (MI) being the most prevalent form. ...