Este trabajo es apoyado por la Fundación Leducq través de la red Caerus (RJH), por el NIH R01 HL093183, HL088434, HL071763, HL080498, HL083156 y P20HL100396 (RJH). DL recibió el apoyo de la Fundación Alemana de Investigación. Nos gustaría dar las gracias a Lauren Leonardson por su asistencia técnica en este proyecto.

1. La creación de infarto de miocardio <ol><li> Mujer cerdos Yorkshire (20 kg) de animales industrias de biotecnología (Doylestown, Pensilvania) se pre-medicado con Telazol (tiletamina / zolazepam) (8,0 mg / kg) y buprenorfina (0,6 mg). </li><li> Los animales son intubados y ventilados con oxígeno al 100%. La anestesia general se mantiene con Propofol (5-8mg/kg/hr) durante todo el procedimiento. </li><li> El sitio femoral se prepara con 70% de alcohol isopropílico seguido de povidona yodada. La punción percutánea permite el acceso a la arteria y la colocación de la vaina. Después de la inserción de la vaina, 3000-5000 UI de heparina se administra IV para mantener un tiempo de coagulación activado de 250-300 segundos. </li><li> Un bolo de amiodarona (75 mg) se administra por vía intramuscular. La inyección intravenosa de una bolsa de 1000 ml de solución salina con amiodarona (75 mg), atropina (2 mg) y acetato de potasio (20 mEq) se inicia y se mantiene con una tasa de 150 ml / h durante todo el procedimiento. </li><li> A 7 P. palo de hockey catéter (Cordis, Miami, FL) se avanza a la arteria coronaria izquierda y una angiografía coronaria se realiza. Una guía de 0,014 pulgadas (Abbott, Park, IL) se introduce en la arteria descendente anterior coronaria (LAD). Un niño de 8 mm de largo, 4.0 mm VOYAGER sobre el alambre-balón (Abbott, Park, IL) se avanza y se ubica en la DA proximal, y el globo se infla para coronaria 3 atm. La oclusión de la DA es confirmada por angiografía. </li><li> Con electrocardiograma continuo y el control hemodinámico, la oclusión se mantiene durante 90 minutos. Arritmias ventriculares malignas en ocasiones puede ocurrir dentro de los primeros 40 minutos, en cuyo caso la entrega inmediata de los impactos directos de corriente de 200 J a 300 J se administran. Por lo general, hay dos marcos de tiempo máximo de arritmia, entre un 2 y 10 minutos y el otro entre 25 y 35 minutos después del inflado del balón. Observación minuciosa y la desfibrilación inmediata son la clave para la creación de infarto de miocardio con éxito, ya que hay más de un 95% de incidencia de entrar en la fibrilación ventricular dentro de los plazos indicados. Si la desfibrilación inmediata y adecuada se lleva a cabo, la tasa de supervivencia es muy alta. Si la presión arterial cae por debajo de 80 mmHg, el volumen de carga se realiza con una rápida infusión de solución salina por vía intravenosa. </li><li> El globo se desinfla y todos los dispositivos se eliminan. </li><li> La remoción de la vaina de la arteria femoral, la anestesia es retenido, y el animal se controla durante la recuperación. Solución salina por vía intravenosa con amiodarona, atropina y la infusión de acetato de potasio, se reduce a 50 ml / hr y se da durante la noche. Una inyección intramuscular de Nitroglycerline y Furoscemide se administra. Entonces el animal se le permite recuperar y cuidado de la monitorización del ECG se mantiene durante al menos 3 horas. </li><li> La aspirina (200 mg) PO se administra durante cinco días. </li></ol> Las complicaciones más frecuentes durante y después del procedimiento de infarto de miocardio son la creación de disección coronaria, hematoma sitio de la punción, arritmia e insuficiencia cardiaca. A perfeccionar la técnica y la supervisión minuciosa es necesaria para prevenir y tratar estas complicaciones. 2. Virus de la inyección <ol><li> Los animales se preparan como se indica en la creación de miocardio infarto steps1-3. La misma dosis de heparina se debe dar para prevenir la trombosis durante la inyección del virus. </li><li> Un catéter 5Fr palo de hockey (Cordis, Miami, FL) se avanza a la arteria coronaria izquierda. Después de la angiografía, dos de los cables de guía de 0,014 pulgadas están avanzadas, una en la LAD y uno en la arteria coronaria circunfleja (LCX) para fijar la posición del catéter. </li><li> Sangre arterial (-20 ml) se extrae de la sonda. Para evitar la isquemia durante la infusión, la mitad de la sangre diluida se utiliza para la solución. El virus se mezcla con la sangre de 10 ml y se diluyó a 20 ml de solución salina. Los restantes 10 ml también se diluye a 20 ml y se utiliza entregar virus residual en la luz del catéter. </li><li> Nitroglicerina por vía intravenosa (20 mg / min) se inicia a través de la vena de la oreja. </li><li> La punta del catéter se coloca en la porción proximal de las vías principales a la izquierda. La presión a través del catéter se controla para asegurar que el catéter no se acuña. </li><li> La sangre del virus mixtos (15 ml) se inyecta a través del catéter de más de 15 minutos usando una bomba de infusión en la arteria coronaria izquierda. Después de 15 minutos, la jeringa se cambia a color, y la infusión se continuó durante 10 minutos. </li><li> Un alambre y un catéter se fija a la arteria coronaria derecha del mismo modo que la arteria coronaria izquierda. </li><li> El restante 5 ml de sangre mezclada con el virus se inyecta en la arteria coronaria derecha durante 5 minutos seguido de 10 minutos de descarga. </li></ol> 3. Representante de casos La figura 1 muestra la ventriculografía izquierda en un mes después de la creación del infarto de miocardio. El movimiento de la pared ventricular izquierda es significativamente afectada con una fracción de eyección (FE) de laEl 31%. La figura 2 muestra las secciones transversales del ventrículo izquierdo en un mes. Una gran cicatriz desde la base hasta el vértice de la pared anterior se ve. El EF promedio de 1 mes después de infarto de miocardio en este modelo es del 36% y el volumen diastólico final promedio es de 83 ml, mientras que el promedio de las de los animales del mismo tamaño, sin un infarto de miocardio es del 68% y 42 ml, respectivamente. La Figura 3 muestra la expresión de beta-gal en el área de la zona del ventrículo izquierdo borde de 1 mes después de la inyección de virus adeno-asociado (2 x 10 12 partículas de DNAsa Resistente rAAV1 CMV Lac-Z). Una mayor expresión se encuentra en la zona de la inyección del virus. <img src="/files/ftp_upload/2778/2778fig1.jpg" alt="Figura 1" /> Fracción de la figura 1. Eyección de ventriculografía izquierda un mes después de la creación de miocardio infarto. Ventrículo izquierdo se dilata a 92,5 ml y movimiento de la pared anterior se ve afectada de manera significativa. <img src="/files/ftp_upload/2778/2778fig2.jpg" alt="Figura 2" /> Figura 2. Las secciones transversales del ventrículo izquierdo, 1 mes después del infarto de miocardio creación, manchado por el cloruro de trifenil tetrazolio para delinear la zona de la cicatriz. Una gran cicatriz desde la base hasta el vértice de la pared anterior se ve. <img src="/files/ftp_upload/2778/2778fig3.jpg" alt="Figura 3" /> Figura 3. Beta-gal expresión inducida por virus adeno-asociado (2 x 10 12 partículas DNAsa resistentes de rAAV1 CMV Lac-Z). Una mayor expresión se encuentra en el área de la zona fronteriza entre el infarto y el tejido normal, un mes después de la inyección intracoronaria de virus. Imagen inferior derecha muestra el control negativo, donde se inyectó una solución salina normal sólo en las arterias coronarias con el mismo protocolo.

<ol>
	<li>Perez de Prado, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Closed-chest+experimental+porcine+model+of+acute+myocardial+infarction-reperfusion.">Closed-chest experimental porcine model of acute myocardial infarction-reperfusion.</a> J Pharmacol Toxicol Methods. 60, 301-306 (2009).</li><li>Angeli, F. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Left+ventricular+remodeling+after+myocardial+infarction:+characterization+of+a+swine+model+on+beta-blocker+therapy.">Left ventricular remodeling after myocardial infarction: characterization of a swine model on beta-blocker therapy.</a> Comp Med. 59, 272-279 (2009).</li><li>Urdaneta, F., Lobato, E. B., Kirby, D. S. &. a. m. p. ;. a. m. p., Sidi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treating+myocardial+stunning+randomly,+with+either+propofol+or+isoflurane+following+transient+coronary+occlusion+and+reperfusion+in+pigs.">Treating myocardial stunning randomly, with either propofol or isoflurane following transient coronary occlusion and reperfusion in pigs.</a> Ann Card Anaesth. 12, 113-121 (2009).</li><li>Jaski, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+upregulation+by+percutaneous+administration+of+gene+therapy+in+cardiac+disease+(CUPID+Trial),+a+first-in-human+phase+1/2+clinical+trial.">Calcium upregulation by percutaneous administration of gene therapy in cardiac disease (CUPID Trial), a first-in-human phase 1/2 clinical trial.</a> J Card Fail. 15, 171-181 (2009).</li></ol>

Todos los autores no tienen asociaciones comerciales que pudieran representar un conflicto de intereses en relación con el manuscrito.

Entre las diversas causas de la insuficiencia cardíaca, isquemia es por mucho el más frecuente en la etiología. Para superar esta grave enfermedad, diversos enfoques terapéuticos se están desarrollando. Cuidadosas evaluaciones de los tratamientos se requieren antes de que estas terapias prometedoras se puede aplicar a las clínicas. Por lo tanto, el establecimiento de un modelo de insuficiencia cardíaca isquémica, que representa las condiciones clínicas de los pacientes es fundamental para el desarrollo de las terapias de insuficiencia cardíaca. Nuestro modelo de infarto de miocardio porcino cumple con los requisitos de traducción. Para inducir insuficiencia cardíaca mediante la creación de un infarto de miocardio, el área de infarto tiene que ser grande. Nuestro modelo tiene una cicatriz grande en comparación con los estudios anteriores, que también se utiliza un modelo de infarto de miocardio endovascular 1. Hemos encontrado que la administración de amiodarona y el mantenimiento de la presión arterial de más de 80 mmHg durante la oclusión coronaria es esencial para aumentar tanto la tasa de supervivencia y de la zona infartada. Mientras que el isoflurano es un anestésico eficaz para este procedimiento 1.2, encontramos que con propofol, una mayor presión sanguínea puede ser mantenido. Además, isoflurano se informó que más de cardio-protección frente a los efectos de propofol 3, y esto podría conducir a una disminución del tamaño del infarto. La terapia génica cardíaco es uno de los enfoques más prometedores para las fallas del corazón, y hay variedad de estrategias para la transferencia del gen. Por encima de todo, la inyección intracoronaria de vectores virales portadores de un gen, es una técnica sencilla y menos invasiva. Varios intentos se hacen para aumentar la expresión génica. Nuestro laboratorio ha encontrado que la infusión de nitroglicerina durante la inyección del virus aumenta la expresión génica (I. Karakikes, inédito). La transferencia de genes de SERCA2a con adeno-asociado vector viral se ha traducido en resultados positivos en humanos 4. Nuevas mejoras en la terapia de genes cardiacos se espera que con los genes de transporte adicionales, así como mejoras vector. Nuestro método de entrega proporciona una transferencia de gen simple y eficiente con una mayor expresión de los genes, y puede ser fácilmente traducido a la clínica.

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		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
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<tr>
<td>Telazol</td>
<td>&nbsp;</td>
<td>Fort Dodge Animal Health</td>
<td>0856-9050-49</td>
<td>&nbsp;</td>
<tr>
<td>Propofol</td>
<td>&nbsp;</td>
<td>APP Pharmaceuticals</td>
<td>63323-270-20</td>
<td>&nbsp;</td>
<tr>
<td>Heparin</td>
<td>&nbsp;</td>
<td>APP Pharmaceuticals</td>
<td>63323-540-11</td>
<td>&nbsp;</td>
<tr>
<td>Amiodarone</td>
<td>&nbsp;</td>
<td>APP Pharmaceuticals</td>
<td>63323-616-03</td>
<td>&nbsp;</td>
<tr>
<td>Atropin Sulfate</td>
<td>&nbsp;</td>
<td>Med-Pharmex</td>
<td>54925-063-10</td>
<td>&nbsp;</td>
<tr>
<td>Potassium acetate</td>
<td>&nbsp;</td>
<td>American Regent, Inc.</td>
<td>2053-25</td>
<td>&nbsp;</td>
<tr>
<td>Nitroglycerine</td>
<td>&nbsp;</td>
<td>American Regent, Inc.</td>
<td>4810-25 </td>
<td>&nbsp;</td>
<tr>
<td>Salix (Furosemide)</td>
<td>&nbsp;</td>
<td>Intervet Inc.</td>
<td>710461</td>
<td>&nbsp;</td>
<tr>
<td>5 Fr Hockey stick catheter</td>
<td>&nbsp;</td>
<td>Cordis</td>
<td>556-278-0L</td>
<td>&nbsp;</td>
<tr>
<td>7 Fr Hockey stick catheter</td>
<td>&nbsp;</td>
<td>Cordis</td>
<td>778-278-00</td>
<td>&nbsp;</td>
<tr>
<td>Coronary wire</td>
<td>&nbsp;</td>
<td>Abbott Laboratories</td>
<td>1044588</td>
<td>&nbsp;</td>
<tr>
<td>Coronary balloon</td>
<td>&nbsp;</td>
<td>Abbott Laboratories</td>
<td>1009447-08</td>
<td>&nbsp;</td>
<tr>
<td>8Fr sheath</td>
<td>&nbsp;</td>
<td>TERUMO</td>
<td>RSS801</td>
<td>&nbsp;</td>		</tbody>
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gene transfer for ischemic heart failure in a preclinical model

Varias tecnologías emergentes se están desarrollando para los pacientes con insuficiencia cardíaca. Bien establecidas las evaluaciones preclínicas son necesarios para determinar su eficacia y seguridad. La terapia génica con vectores virales es uno de los enfoques más prometedores para el tratamiento de las enfermedades cardíacas. Entrega viral de varios genes diferentes, cambiando el portador del gen tiene un potencial terapéutico incalculable. En este video, el proceso completo de un modelo animal de la creación de la insuficiencia cardíaca seguida de la transferencia de genes se presenta con un modelo porcino. En primer lugar, el infarto de miocardio es creado por la oclusión de la descendente anterior izquierda proximal arterias coronarias. Resultados corazón de remodelación en la insuficiencia cardíaca crónica. Único en nuestro modelo es una cicatriz bastante grande que refleje verdaderamente los pacientes con insuficiencia cardíaca grave que requieren una terapia agresiva para lograr resultados positivos. Después de la creación de miocardio infarto y el desarrollo de tejido cicatricial, una inyección intracoronaria de virus se demuestra con la infusión de nitroglicerina simultánea. Nuestro método de inyección proporciona una transferencia de gen simple y eficiente con una mayor expresión de los genes. Esta combinación de un infarto de miocardio modelo de cerdos con el virus de la entrega intracoronaria ha demostrado ser una metodología consistente y reproducible, lo que ayuda no sólo para probar el efecto de los genes individuales, sino también comparar la eficacia de muchos genes como candidatos terapéuticos.

Watch this Scientific Journal Video about Gene Transfer for Ischemic Heart Failure in a Preclinical Model at JoVE.com

Gene Transfer for Ischemic Heart Failure in a Preclinical Model

Un método de transferencia génica para el tratamiento de la insuficiencia cardíaca isquémica se describe usando un modelo porcino de infarto de miocardio. Nuestro método simple y reproducible que nos permite evaluar fácilmente la eficacia de la transferencia de genes diferentes con una forma muy sencilla y reproducible.

Transferencia génica para la insuficiencia cardiaca isquémica en un modelo preclínico

Various emerging technologies are being developed for patients with heart failure. Well-established preclinical evaluations are necessary to determine ...

gene-transfer-for-ischemic-heart-failure-in-a-preclinical-model

Nanyang Technological University

Research

JoVE Journal

Medicine

12.8K vistas.  Mount Sinai School of Medicine. Un método de transferencia génica para el tratamiento de la insuficiencia cardíaca isquémica se describe usando un modelo porcino de infarto de miocardio. Nuestro método simple y reproducible que nos permite evaluar fácilmente la eficacia de la transferencia de genes diferentes con una forma muy sencilla y reproducible.

Video: Gene Transfer for Ischemic Heart Failure in a Preclinical Model

A Simplified Technique for Producing an Ischemic Wound Model

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work well in non-ischemic wounds may not work in human diabetic wounds because vasculopathy is one major factor that hinders healing of these wounds. We published an article in 2007 describing a rabbit ear ischemic wound model created by a minimally invasive surgical technique. Since then, we have further simplified the procedure for easier operation. On one ear, three small skin incisions were made on the vascular pedicles, 1-2 cm from the ear base. The central artery was ligated and cut along with the nerve. The whole cranial bundle was cut and ligated, leaving only the caudal branch intact. A circumferential subcutaneous tunnel was made through the incisions, to cut subcutaneous tissues, muscles, nerves, and small vessels. The other ear was used as a non-ischemic control. Four wounds were made on the ventral side of each ear. This technique produces 4 ischemic wounds and 4 non-ischemic wounds in one animal for paired comparisons. After surgery, the ischemic ear was cool and cyanotic, and showed reduced movement and a lack of pulse in the ear artery. Skin temperature of the ischemic ear was 1-10 &deg;C lower than that on the normal ear and this difference was maintained for more than one month. Ear tissue high-energy phosphate contents were lower in the ischemic ear than the control ear. Wound healing times were longer in the ischemic ear than in the non-ischemic ear when the same treatment was used. The technique has now been used on more than 80 rabbits in which 23 were diabetic (diabetes time ranging from 2 weeks to 2 years). No single rabbit has developed any surgical complications such as bleeding, infection, or rupture in the skin incisions. The model has many advantages, such as little skin disruption, longer ischemic time, and higher success rate, when compared to many other models. It can be safely used in animals with reduced resistance, and can also be modified to meet different testing requirements.

We have developed a minimally invasive technique to create a rabbit ischemic ear wound model by dividing the central artery and nerve and the cranial neurovascular bundle. A subcutaneous tunnel then cuts all subcutaneous tissues. This procedure causes minimal skin disruption and can be safely used in diabetic animals.

Una técnica simplificada para fabricar un modelo de lesión isquémica

One major obstacle in current diabetic wound research is a lack of an ischemic wound model that can be safely used in diabetic animals. Drugs that work ...

Investigación

Medicina

A Preclinical Murine Model of Hepatic Metastases

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, murine pancreatic tumor model of hepatic metastases via a hemispleen injection of syngeneic murine pancreatic tumor cells is described. This model mimics many of the clinical conditions in patients with metastatic disease to the liver. Mice consistently develop metastases in the liver allowing for investigation of the metastatic process, experimental therapy testing, and tumor immunology research.

A preclinical, murine model of hepatic metastases performed via a hemispleen injection technique.

A preclínicos modelo murino de metástasis hepática

Numerous murine models have been developed to study human cancers and advance the understanding of cancer treatment and development. Here, a preclinical, ...

Permanent Ligation of the Left Anterior Descending Coronary Artery in Mice: A Model of Post-myocardial Infarction Remodelling and Heart Failure

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It is characterized by fluid retention, shortness of breath, and fatigue, in particular on exertion. Heart failure is a growing public health problem, the leading cause of hospitalization, and a major cause of mortality. Ischemic heart disease is the main cause of heart failure.
Ventricular remodelling refers to changes in structure, size, and shape of the left ventricle. This architectural remodelling of the left ventricle is induced by injury (e.g., myocardial infarction), by pressure overload (e.g., systemic arterial hypertension or aortic stenosis), or by volume overload. Since ventricular remodelling affects wall stress, it has a profound impact on cardiac function and on the development of heart failure. A model of permanent ligation of the left anterior descending coronary artery in mice is used to investigate ventricular remodelling and cardiac function post-myocardial infarction. This model is fundamentally different in terms of objectives and pathophysiological relevance compared to the model of transient ligation of the left anterior descending coronary artery. In this latter model of ischemia/reperfusion injury, the initial extent of the infarct may be modulated by factors that affect myocardial salvage following reperfusion. In contrast, the infarct area at 24 hr after permanent ligation of the left anterior descending coronary artery is fixed. Cardiac function in this model will be affected by 1) the process of infarct expansion, infarct healing, and scar formation; and 2) the concomitant development of left ventricular dilatation, cardiac hypertrophy, and ventricular remodelling.
Besides the model of permanent ligation of the left anterior descending coronary artery, the technique of invasive hemodynamic measurements in mice is presented in detail.

Heart failure is the leading cause of hospitalization and a major cause of mortality. A model of permanent ligation of the left anterior descending coronary artery in mice is applied to investigate ventricular remodelling and cardiac dysfunction post-myocardial infarction. The technique of invasive hemodynamic measurements in mice is presented.

La ligadura permanente de la arteria coronaria descendente anterior en ratones: un modelo de remodelación post infarto de miocardio e insuficiencia cardiaca

Heart failure is a syndrome in which the heart fails to pump blood at a rate commensurate with cellular oxygen requirements at rest or during stress. It ...

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves focal endothelial-selective transgenesis, thereby allowing an investigator to determine the biological roles of endothelial-expressed transgenes and to quantify the in vivo transcriptional activity of DNA sequences in large artery endothelial cells. The method uses surgical isolation of rabbit common carotid arteries and an arteriotomy to deliver a transgene-expressing viral vector into the arterial lumen. A short incubation period of the vector in the lumen, with subsequent aspiration of the lumen contents, is sufficient to achieve efficient and durable expression of the transgene in the endothelium, with no detectable transduction or expression outside of the isolated arterial segment. The method allows assessment of the biological activities of transgene products both in normal arteries and in models of human vascular disease, while avoiding systemic effects that could be caused either by targeting gene delivery to other sites (e.g. the liver) or by the alternative approach of delivering genetic constructs to the endothelium by germ line transgenesis. Application of the method is limited by the need for a skilled surgeon and anesthetist, a well-equipped operating room, the costs of purchasing and housing rabbits, and the need for expertise in gene-transfer vector construction and use. Results obtained with this method include: transgene-related alterations in arterial structure, cellularity, extracellular matrix, or vasomotor function; increases or reductions in arterial inflammation; alterations in vascular cell apoptosis; and progression, retardation, or regression of diseases such as intimal hyperplasia or atherosclerosis. The method also allows measurement of the ability of native and synthetic DNA regulatory sequences to alter transgene expression in endothelial cells, providing results that include: levels of transgene mRNA, levels of transgene protein, and levels of transgene enzymatic activity.

In Vivo Gene Transfer to the Rabbit Common Carotid Artery Endothelium

This method is to introduce a transgene into the endothelium of rabbit carotid arteries. Introduction of the transgene allows the assessment of the biological role of the transgene product either in normal arteries or disease models. The method is also useful for measuring activity of DNA regulatory sequences.

En Vivo Transferencia génica en el endotelio de la arteria carótida común conejo

The goal of this method is to introduce a transgene into the endothelium of isolated segments of both rabbit common carotid arteries. The method achieves ...

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment methods. Here, we present such a model by tachycardia-induced cardiomyopathy, which can be produced by rapid cardiac pacing in swine.
A single pacing lead is introduced transvenously into fully anaesthetized healthy swine, to the apex of the right ventricle, and fixated. Its other end is then tunneled dorsally to the paravertebral region. There, it is connected to an in-house modified heart pacemaker unit that is then implanted in a subcutaneous pocket. 
After 4 - 8 weeks of rapid ventricular pacing at rates of 200 - 240 beats/min, physical examination revealed signs of severe heart failure - tachypnea, spontaneous sinus tachycardia, and fatigue. Echocardiography and X-ray showed dilation of all heart chambers, effusions, and severe systolic dysfunction. These findings correspond well to decompensated dilated cardiomyopathy and are also preserved after the cessation of pacing.
This model of tachycardia-induced cardiomyopathy can be used for studying the pathophysiology of progressive chronic heart failure, especially hemodynamic changes caused by new treatment modalities like mechanical circulatory supports. This methodology is easy to perform and the results are robust and reproducible.

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

Cardiomiopatía Taquicardia-inducida como un modelo de insuficiencia cardíaca crónica en porcino

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment ...

Isolation of Atrial Cardiomyocytes from a Rat Model of Metabolic Syndrome-related Heart Failure with Preserved Ejection Fraction

In this article, we describe an optimized, Langendorff-based procedure for the isolation of single-cell atrial cardiomyocytes (ACMs) from a rat model of metabolic syndrome (MetS)-related heart failure with preserved ejection fraction (HFpEF). The prevalence of MetS-related HFpEF is rising, and atrial cardiomyopathies associated with atrial remodeling and atrial fibrillation are clinically highly relevant as atrial remodeling is an independent predictor of mortality. Studies with isolated single-cell cardiomyocytes are frequently used to corroborate and complement in vivo findings. Circulatory vessel rarefication and interstitial tissue fibrosis pose a potentially limiting factor for the successful single-cell isolation of ACMs from animal models of this disease.
We have addressed this issue by employing a device capable of manually regulating the intraluminal pressure of cardiac cavities during the isolation procedure, substantially increasing the yield of morphologically and functionally intact ACMs. The acquired cells can be used in a variety of different experiments, such as cell culture and functional Calcium imaging (i.e., excitation-contraction-coupling).
We provide the researcher with a step-by-step protocol, a list of optimized solutions, thorough instructions to prepare the necessary equipment, and a comprehensive troubleshooting guide. While the initial implementation of the procedure might be rather difficult, a successful adaptation will allow the reader to perform state-of-the-art ACM isolations in a rat model of MetS-related HFpEF for a broad spectrum of experiments.

Here, we describe an optimized, Langendorff-based procedure for the isolation of single-cell atrial cardiomyocytes from a rat model of metabolic syndrome-related heart failure with preserved ejection fraction. A manual regulation of intraluminal pressure of cardiac cavities is implemented to yield functionally intact myocytes suitable for excitation-contraction-coupling studies.

Aislamiento de cardiomiocitos auricular de un modelo de rata de la falta de corazón relacionados con el síndrome metabólico con fracción de eyección preservada

In this article, we describe an optimized, Langendorff-based procedure for the isolation of single-cell atrial cardiomyocytes (ACMs) from a rat model of ...

Preclinical Model of Hind Limb Ischemia in Diabetic Rabbits

Peripheral vascular disease is a widespread clinical problem that affects millions of patients worldwide. A major consequence of peripheral vascular disease is the development of ischemia. In severe cases, patients can develop critical limb ischemia in which they experience constant pain and an increased risk of limb amputation. Current therapies for peripheral ischemia include bypass surgery or percutaneous interventions such as angioplasty with stenting or atherectomy to restore blood flow. However, these treatments often fail to the continued progression of vascular disease or restenosis or are contraindicated due to the overall poor health of the patient. A promising potential approach to treat peripheral ischemia involves the induction of therapeutic neovascularization to allow the patient to develop collateral vasculature. This newly formed network alleviates peripheral ischemia by restoring perfusion to the affected area. The most frequently employed preclinical model for peripheral ischemia utilizes the creation of hind limb ischemia in healthy rabbits through femoral artery ligation. In the past, however, there has been a strong disconnect between the success of preclinical studies and the failure of clinical trials regarding treatments for peripheral ischemia. Healthy animals typically have robust vascular regeneration in response to surgically induced ischemia, in contrast to the reduced vascularity and regeneration in patients with chronic peripheral ischemia. Here, we describe an optimized animal model for peripheral ischemia in rabbits that includes hyperlipidemia and diabetes. This model has reduced collateral formation and blood pressure recovery in comparison to a model with a higher cholesterol diet. Thus, the model may provide better correlation with human patients with compromised angiogenesis from the common co-morbidities that accompany peripheral vascular disease.

We describe a surgical procedure used to induce peripheral ischemia in rabbits with hyperlipidemia and diabetes. This surgery acts as a preclinical model for conditions experienced in peripheral artery disease in patients. Angiography is also described as a means to measure the extent of introduced ischemia and recovery of perfusion.

Modelo preclínico de isquemia de extremidades traseras en conejos diabéticos

Peripheral vascular disease is a widespread clinical problem that affects millions of patients worldwide. A major consequence of peripheral vascular ...

Establishing a Swine Model of Post-myocardial Infarction Heart Failure for Stem Cell Treatment

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major causes of mortality and morbidity around the world. Cell-based therapies for cardiac repair and improvement of left ventricular function after MI have attracted considerable attention. Accordingly, the safety and efficacy of these cell transplantations should be tested in a preclinical large animal model of HF prior to clinical use. Pigs are widely used for cardiovascular disease research due to their similarity to humans in terms of heart size and coronary anatomy. Therefore, we sought to present an effective protocol for the establishment of a porcine chronic HF model using closed-chest coronary balloon occlusion of the left circumflex artery (LCX), followed by rapid ventricular pacing induced with pacemaker implantation. Eight weeks later, the stem cells were administered by intramyocardial injection in the peri-infarct area. Then the infarct size, cell survival, and left ventricular function (including echocardiography, hemodynamic parameters, and electrophysiology) were evaluated. This study helps establish a stable preclinical large animal HF model for stem cell treatment.

We sought to establish a swine model of heart failure induced by left circumflex artery blockage and rapid pacing to test the effect and safety of intramyocardial administration of stem cells for cell-based therapies.

Establecer un modelo porcino de infarto de infarto post-miocardio insuficiencia cardíaca para el tratamiento de células madre

Although advances have been achieved in the treatment of heart failure (HF) following myocardial infarction (MI), HF following MI remains one of the major ...

A Preclinical Model of Exertional Heat Stroke in Mice

Heat stroke is the most severe manifestation of heat-related illnesses. Classic heat stroke (CHS), also known as passive heat stroke, occurs at rest, whereas exertional heat stroke (EHS) occurs during physical activity. EHS differs from CHS in etiology, clinical presentation, and sequelae of multi-organ dysfunction. Until recently, only models of CHS have been well established. This protocol aims to provide guidelines for a refined preclinical mouse model of EHS that is free from major limiting factors such as the use of anesthesia, restraint, rectal probes, or electric shock. Male and female C57Bl/6 mice, instrumented with core temperature (Tc) telemetric probes were utilized in this model. For familiarization with the running mode, mice undergo 3 weeks of training using both voluntary and forced running wheels. Thereafter, mice run on a forced wheel inside a climatic chamber set at 37.5 &#176;C and 40%-50% relative humidity (RH) until displaying symptom limitation (e.g., loss of consciousness) at Tc of 42.1-42.5 &#176;C, although suitable results can be obtained at chamber temperatures between 34.5-39.5 &#176;C and humidity between 30%-90%. Depending on the desired severity, mice are removed from the chamber immediately for recovery in ambient temperature or remain in the heated chamber for a longer duration, inducing a more severe exposure and a higher incidence of mortality. Results are compared with sham-matched exercise controls (EXC) and/or na&#239;ve controls (NC). The model mirrors many of the pathophysiological outcomes observed in human EHS, including loss of consciousness, severe hyperthermia, multi-organ damage as well as inflammatory cytokine release, and acute phase responses of the immune system. This model is ideal for hypothesis-driven research to test preventative and therapeutic strategies that may delay the onset of EHS or reduce the multi-organ damage that characterizes this manifestation.

The protocol describes the development of a standardized, repeatable, preclinical model of exertional heat stroke (EHS) in mice free from adverse external stimuli such as electric shock. The model provides a platform for mechanistic, preventative, and therapeutic studies.

Un modelo preclínico de golpe de calor por esfuerzo en ratones

Heat stroke is the most severe manifestation of heat-related illnesses. Classic heat stroke (CHS), also known as passive heat stroke, occurs at rest, ...

Large Animal Model for Evaluating the Efficacy of the Gene Therapy in Ischemic Heart

Coronary artery disease is one of the significant causes of mortality and morbidity worldwide. Despite the progression of current therapeutics, a considerable proportion of coronary artery disease patients remain symptomatic. Gene therapy-mediated therapeutic angiogenesis offers a novel therapeutic method for improving myocardial perfusion and relieving symptoms. Gene therapy with different angiogenic factors has been studied in few clinical trials. Due to the novelty of the method, the progress of myocardial gene therapy is a continuous path from bench to bedside. Therefore, large animal models are needed for evaluating the safety and efficacy. The more the large animal model identifies the original disease and the endpoints used in clinics, the more predictable outcomes are from clinical trials. Here, we introduce a large animal model for evaluating the efficacy of the gene therapy in the ischemic porcine heart. We use clinically relevant imaging methods such as ultrasound imaging and 15H2O-PET. For targeting the gene transfers into the desired area, electroanatomical mapping is used. The aim of this method is: (1) to mimic chronic coronary artery disease, (2) to induce therapeutic angiogenesis at hypoxic areas of the heart, and (3) to evaluate the safety and efficacy of the gene therapy by using relevant endpoints.

Myocardial gene therapy for ischemic heart disease holds great promise for future therapeutics. Here, we introduce a large animal model for evaluating the efficacy of gene therapy in the ischemic heart.