L&#39;auteur aimerait remercier le financement du NHLBI (K08 HL102066 et R01 HL114832).

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</ol>

The author has nothing to disclose.

Il y a trois étapes critiques dans cette procédure: 1) la mise en place du tube d&#39;intubation et une ventilation appropriée, 2) mise en place du cathéter IV jugulaire, et 3) la mise en place correcte du cathéter de PV dans le ventricule gauche. Détermination de la fréquence respiratoire appropriée est une partie importante de fournir une assistance ventilatoire. souris conscientes maintiennent généralement la ventilation alvéolaire avec peu profondes respirations rapides. En général, les souris ventilée...

Les maladies cardiovasculaires continue d&#39;être une cause importante de mortalité et de morbidité dans le monde entier 1. Les maladies du cœur présentent des défis particulièrement difficiles dans le développement de nouvelles thérapies. Les progrès en génétique prévoient la possibilité d&#39;identifier une multitude de contributeurs potentiels génétiques au développement de maladies cardiaques. Le caractère intégrateur du système cardio-vasculaire exige que ces cibles génétiques validés dans des modèles animaux intacts. La flexibilité et le faible coût du logement génétiques de la souris ont apporté à l&#39;avant-garde pour l&#39;évaluation du rôle physiologique d&#39;un gène donné. La petite taille de la souris présente des défis uniques pour l&#39;évaluation de la fonction cardiaque. Il existe plusieurs modalités qui peuvent fournir des informations sur la fonction cardiaque, mais seule la mesure simultanée de la pression et du volume ventriculaire permet pression-volume (PV) d&#39;analyse de la boucle de la fonction ventriculaire. PV boucles toutoe la fonction cardiaque devant être analysé indépendamment de sa connexion au système vasculaire; un facteur important pour déterminer le rôle fonctionnel d&#39;un élément génétique particulier. L&#39;évaluation des boucles pression-volume a été utilisé expérimentalement et cliniquement depuis de nombreuses années et abondante littérature existe en ce qui concerne l&#39;analyse de ces ensembles de données 2,3. L&#39;adaptation de la technologie de boucle PV à la souris a été un progrès important pour la compréhension de la physiologie cardiaque murin 4-6. Cathéter à base couplent technologies de boucle PV un capteur de pression et l&#39;utilisation de conductance pour estimer le volume ventriculaire. Le volume ventriculaire est déterminée en examinant les variations d&#39;un champ électrique généré par le cathéter. Cette méthode modélise le ventricule d&#39;un cylindre, dont la hauteur est définie par la distance entre les électrodes sur le cathéter et le rayon est calculé à partir de conduction d&#39;un champ électrique à travers le sangle ventricule 7-9. Le signal de conductance mesuré par le cathéter comporte deux volets. Le premier est la conduction à travers le sang; celle-ci varie avec le volume du ventricule et constitue le signal principal utilisé pour déterminer le volume ventriculaire. Le second composant résulte de la conduction à travers et le long de la paroi du ventricule. Ceci est appelé conductance parallèle et doit être retiré afin de déterminer le volume ventriculaire absolue. Il existe deux systèmes disponibles dans le commerce pour la collecte de données pression-volume dans le laboratoire de recherche et la méthode utilisée pour calculer et retirer la conductance parallèle est la principale différence entre les 6,10,11. cathéters de conductance nécessitent l&#39;injection d&#39;une solution saline hypertonique pour le calcul de la conductance parallèle. Cette injection modifie transitoirement la conductivité du sang dans le ventricule, tandis que la conductivité de la paroi reste constante. A partir de ces données, il est possible de déterminer lacomposante du signal de conductance qui provient du sang et provient de ce que la paroi ventriculaire. Cette approche suppose que la conductance parallèle ne varie pas au cours du cycle cardiaque. La méthode d&#39;admission repose sur des changements de phase dans le champ électrique pour évaluer la contribution de la paroi ventriculaire au signal de volume global. Cette méthode repose sur une série de constantes prédéterminées pour la conductivité du sang et du myocarde afin de déterminer le volume final, mais permet des mesures en continu de la conductance parallèle au cours du cycle cardiaque. Ces deux systèmes fournissent de bonnes estimations du volume ventriculaire gauche et les différences entre eux ne sont pas susceptibles d&#39;être physiologiquement significative. Le modèle cylindrique du ventricule et d&#39;autres hypothèses rendent ces approches à base de cathéter pas aussi précis que d&#39;autres modalités, mais ces données sont fournies sur une base battement par battement qui est essentiel pour l&#39;évaluation de la charge des mesures indépendantes de la fonction cardiaque. La procédure décrite ici est utilisée dans mon laboratoire et a fourni des données pour un grand nombre d&#39;études portant sur ​​les mécanismes physiopathologiques de base de dystrophique cardiomyopathie 12-18. La procédure décrite ci-dessous est l&#39;un des deux qui peut être utilisé pour obtenir des données de boucle PV. Bien que bon nombre des principes sont applicables pour les deux approches, ce protocole mettra l&#39;accent sur une approche apical à thorax ouvert; un protocole de poitrine fermée a été détaillée ailleurs 19,20. Alors que la procédure sera décrite en détail, les principes généraux importants pour exposer le cœur avec un minimum de dommages, soit le cœur ou les poumons. Tout au long du protocole, il est important de se rappeler que c&#39;est une procédure non-survie et que d&#39;avoir une bonne exposition du cœur est d&#39;une importance cruciale pour la bonne mise en place du cathéter.

<table><tbody><tr><td>Dumont 5/45 (2)</td><td>Fine Science Tools</td><td>11251-33</td><td></td></tr><tr><td>Vessel Dilating Forceps</td><td>Fine Science Tools</td><td>18153-11</td><td></td></tr><tr><td>Castroviejo Micro Dissecting Spring Scissor</td><td>Roboz Instruments</td><td>RS-5668</td><td></td></tr><tr><td>Octogon Forceps - Serrated/Curved</td><td>Fine Science Tools</td><td>11041-08</td><td></td></tr><tr><td>Octogon Forceps - Serrated/Straight</td><td>Fine Science Tools</td><td>11040-08</td><td></td></tr><tr><td>Dissector Scissors- Heavy Blade</td><td>Fine Science Tools</td><td>14082-09</td><td></td></tr><tr><td>Transpore Surgical Tape</td><td>3M</td><td>1527-1</td><td></td></tr><tr><td>3-0 Silk Suture</td><td>Fine Science Tools</td><td>18020-30</td><td></td></tr><tr><td>TOPO Ventilator</td><td>Kent Scientific</td><td>TOPO</td><td></td></tr><tr><td>Martin ME 102 Electrosurgical Unit</td><td>Harvard Apparatus</td><td>PY2 72-2484</td><td></td></tr><tr><td>Syringe Pump</td><td>Lucca Technologies</td><td>GenieTouch</td><td></td></tr><tr><td>Stereomicroscope with boom stand</td><td>Nikon</td><td>SMZ-800N</td><td></td></tr><tr><td>Thermocouple Thermometer</td><td>Cole Parmer</td><td>EW-91100-40</td><td></td></tr><tr><td>T/Pump Warm Water Recirculator</td><td>Kent Scientific</td><td>TP-700</td><td></td></tr><tr><td>ADVantage Pressure-Volume System</td><td>Transonic</td><td>ADV500</td><td></td></tr><tr><td>Data Acquision and Analysis</td><td>DSI</td><td>Ponemah ACQ-16</td><td></td></tr></tbody></table>

measuring pressure volume loops in the mouse

Comprendre les causes et la progression de la maladie cardiaque présente un défi important pour la communauté biomédicale. La flexibilité génétique de la souris offre un grand potentiel pour explorer la fonction cardiaque au niveau moléculaire. La petite taille de la souris présente des défis en ce qui concerne l&#39;exécution phénotypage cardiaque détaillée. Miniaturisation et d&#39;autres progrès technologiques ont fait de nombreuses méthodes d&#39;évaluation cardiaque possible chez la souris. Parmi ceux-ci, la collecte simultanée des données de pression et de volume fournit une image détaillée de la fonction cardiaque qui ne sont pas disponibles par le biais de toute autre modalité. Voici une procédure détaillée pour la collecte de données en boucle pression-volume est décrit. Inclus est une discussion sur les principes qui sous-tendent les mesures et les sources potentielles d&#39;erreur. la gestion Anesthetic et approches chirurgicales sont discutées en détail car ils sont à la fois critique pour obtenir la mesure hémodynamique de haute qualités. Les principes du développement du protocole hémodynamique et les aspects pertinents de l&#39;analyse des données sont également abordées.

Par convention, le volume est tracée sur l&#39;axe X et la pression sur l&#39;axe des Y comme dans la figure 1. Les boucles pression-volume résultant d&#39; une pression de traçage en fonction du volume doit ressembler à un rectangle dont les arêtes verticales représentant la variation isovolumiques de la pression ( à savoir, lorsque les deux valves mitrale et aortique sont fermés). L &#39;horizontale inférieure représente le remplissage du ventricule ...

Watch this Scientific Journal Video about Measuring Pressure Volume Loops in the Mouse at JoVE.com

Measuring Pressure Volume Loops in the Mouse

Ce manuscrit décrit un protocole détaillé pour la collecte de données de pression-volume de la souris.

Mesure de boucles de volume de pression chez la souris

Understanding the causes and progression of heart disease presents a significant challenge to the biomedical community. The genetic flexibility of the ...

measuring-pressure-volume-loops-in-the-mouse

Research

JoVE Journal

Biology

16.3K vues.  University of Minnesota.  Ce manuscrit décrit un protocole détaillé pour la collecte de données de pression-volume de la souris. 

Vidéo: Measuring Pressure Volume Loops in the Mouse

Measuring Left Ventricular Pressure in Late Embryonic and Neonatal Mice

Blood pressure increases significantly during embryonic and postnatal development in vertebrate animals. In the mouse, blood flow is first detectable around embryonic day (E) 8.51. Systolic left ventricular (LV) pressure is 2 mmHg at E9.5 and 11 mmHg at E14.52. At these mid-embryonic stages, the LV is clearly visible through the chest wall for invasive pressure measurements because the ribs and skin are not fully developed. Between E14.5 and birth (approximately E21) imaging methods must be used to view the LV. After birth, mean arterial pressure increases from 30 - 70 mmHg from postnatal day (P) 2 - 353. Beyond P20, arterial pressure can be measured with solid-state catheters (i.e. Millar or Scisense). Before P20, these catheters are too big for developing mouse arteries and arterial pressure must be measured with custom pulled plastic catheters attached to fluid-filled pressure transducers3 or glass micropipettes attached to servo null pressure transducers4.
Our recent work has shown that the greatest increase in blood pressure occurs during the late embryonic to early postnatal period in mice5-7. This large increase in blood pressure may influence smooth muscle cell (SMC) phenotype in developing arteries and trigger important mechanotransduction events. In human disease, where the mechanical properties of developing arteries are compromised by defects in extracellular matrix proteins (i.e. Marfan's Syndrome8 and Supravalvular Aortic Stenosis9) the rapid changes in blood pressure during this period may contribute to disease phenotype and severity through alterations in mechanotransduction signals. Therefore, it is important to be able to measure blood pressure changes during late embryonic and neonatal periods in mouse models of human disease.
We describe a method for measuring LV pressure in late embryonic (E18) and early postnatal (P1 - 20) mice. A needle attached to a fluid-filled pressure transducer is inserted into the LV under ultrasound guidance. Care is taken to maintain normal cardiac function during the experimental protocol, especially for the embryonic mice. Representative data are presented and limitations of the protocol are discussed.

Measuring left ventricular pressure (LV) in embryonic and neonatal mice is described. Pressure is measured by inserting a needle connected to a fluid-filled transducer into the LV under ultrasound guidance. Care must be taken to maintain normal cardiac function during the experimental protocol.

Mesure de la pression ventriculaire gauche à la fin de souris embryonnaires et néonatale

Blood pressure increases significantly during embryonic and postnatal development in vertebrate animals. In the mouse, blood flow is first detectable ...

Recherche

Bio-ingénierie

Right Ventricular Systolic Pressure Measurements in Combination with Harvest of Lung and Immune Tissue Samples in Mice

The function of the right heart is to pump blood through the lungs, thus linking right heart physiology and pulmonary vascular physiology. Inflammation is a common modifier of heart and lung function, by elaborating cellular infiltration, production of cytokines and growth factors, and by initiating remodeling processes 1.
Compared to the left ventricle, the right ventricle is a low-pressure pump that operates in a relatively narrow zone of pressure changes. Increased pulmonary artery pressures are associated with increased pressure in the lung vascular bed and pulmonary hypertension 2. Pulmonary hypertension is often associated with inflammatory lung diseases, for example chronic obstructive pulmonary disease, or autoimmune diseases 3. Because pulmonary hypertension confers a bad prognosis for quality of life and life expectancy, much research is directed towards understanding the mechanisms that might be targets for pharmaceutical intervention 4. The main challenge for the development of effective management tools for pulmonary hypertension remains the complexity of the simultaneous understanding of molecular and cellular changes in the right heart, the lungs and the immune system.
Here, we present a procedural workflow for the rapid and precise measurement of pressure changes in the right heart of mice and the simultaneous harvest of samples from heart, lungs and immune tissues. The method is based on the direct catheterization of the right ventricle via the jugular vein in close-chested mice, first developed in the late 1990s as surrogate measure of pressures in the pulmonary artery5-13. The organized team-approach facilitates a very rapid right heart catheterization technique. This makes it possible to perform the measurements in mice that spontaneously breathe room air. The organization of the work-flow in distinct work-areas reduces time delay and opens the possibility to simultaneously perform physiology experiments and harvest immune, heart and lung tissues.
The procedural workflow outlined here can be adapted for a wide variety of laboratory settings and study designs, from small, targeted experiments, to large drug screening assays. The simultaneous acquisition of cardiac physiology data that can be expanded to include echocardiography5,14-17 and harvest of heart, lung and immune tissues reduces the number of animals needed to obtain data that move the scientific knowledge basis forward. The procedural workflow presented here also provides an ideal basis for gaining knowledge of the networks that link immune, lung and heart function. The same principles outlined here can be adapted to study other or additional organs as needed.

A specific and rapid protocol to simultaneously investigate right heart function, lung inflammation, and the immune response is described as a learning tool. Video and figures describe physiology and microdissection techniques in an organized team-approach that is adaptable to be used for small to large sized studies.

Mesures systolique ventriculaire droite pression en combinaison avec la récolte du poumon et des échantillons de tissus immunitaires chez des souris

The function of the right heart is to pump blood through the lungs, thus linking right heart physiology and pulmonary vascular physiology. Inflammation is ...

Immunologie et infection

Measuring Blood Pressure in Mice using Volume Pressure Recording, a Tail-cuff Method

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. The CODA tail-cuff system uses Volume Pressure Recording (VPR) to measure the blood pressure by determining the tail blood volume. A specially designed differential pressure transducer and an occlusion tail-cuff measure the total blood volume in the tail without the need to obtain the individual pulse signal. Special attention is afforded to the length of the occlusion cuff in order to derive the most accurate blood pressure readings. VPR can easily obtain readings on dark-skinned rodents, such as C57BL6 mice and is MRI compatible. The CODA system provides you with measurements of six (6) different blood pressure parameters; systolic and diastolic blood pressure, heart rate, mean blood pressure, tail blood flow, and tail blood volume. Measurements can be made on either awake or anesthetized mice or rats. The CODA system includes a controller, laptop computer, software, cuffs, animal holders, infrared warming pads, and an infrared thermometer. There are seven different holder sizes for mice as small as 8 grams to rats as large as 900 grams.

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. This tail-cuff system uses Volume Pressure Recording (VPR) to measure the blood pressure by determining the tail blood volume.

Mesurer la pression sanguine chez des souris en utilisant enregistrement de la pression du volume, une méthode Queue-coiffe

The CODA 8-Channel High Throughput Non-Invasive Blood Pressure system measures the blood pressure in up to 8 mice or rats simultaneously. The CODA ...

Biologie

Catheterization of Intestinal Loops in Ruminants

The intestine is a complex structure that is involved not only in absorption of nutrients, but also acts as a barrier between the individual and the outside world. As such, the intestine plays a pivotal role in immunosurveillance and protection from enteric pathogens. Investigating intestinal physiology and immunology commonly employs 'intestinal loops' as an experimental model. The majority of these loop models are non-recovery surgical procedures that study short-term (&lt;24 hr) changes in the intestine (1-3). We previously created a recovery intestinal loop model to specifically measure long-term (&lt;6 mo) immunological changes in the intestine of sheep following exposure to vaccines, adjuvants, and viruses (4). This procedure localized treatments to a specific 'loop', allowing us to sample this area of the intestine. A significant drawback of this method is the single window of opportunity to administer treatments (i.e. at the time of surgery). Furthermore, samples of both the intestinal mucosa and luminal contents can only be taken at the termination of the project. Other salient limitations of the above model are that the surgical manipulation and requisite post-operative measures (e.g. administration of antibiotics and analgesics) can directly affect the treatment itself and/or alter immune function, thereby confounding results. Therefore, we modified our intestinal loop model by inserting long-term catheters into the loops. Sheep recover fully from the procedure, and are unaffected by the exteriorized catheters. Notably, the establishment of catheters in loops allows us to introduce multiple treatments over an extended interval, following recovery from surgery and clearance of drugs administered during surgery and the post-operative period.

We describe a novel surgical method for catheterizing 'intestinal loops' within the ileum of sheep. Once animals have recovered from surgery and have cleared antibiotics and analgesics, multiple treatments can be deposited directly in loops via the catheters.

Cathétérisme des anses intestinales chez les ruminants

The intestine is a complex structure that is involved not only in absorption of nutrients, but also acts as a barrier between the individual and the ...

Measurement of the Pressure-volume Curve in Mouse Lungs

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential phenotypic changes are best assessed by measurement of the changes in lung elasticity. To best understand specific mechanisms underlying such pathologies in mice, it is essential to make functional measurements that can reflect the developing pathology. Although there are many ways to measure elasticity, the classical method is that of the total lung pressure-volume (PV) curve done over the whole range of lung volumes. This measurement has been made on adult lungs from nearly all mammalian species dating back almost 100 years, and such PV curves also played a major role in the discovery and understanding of the function of pulmonary surfactant in fetal lung development. Unfortunately, such total PV curves have not been widely reported in the mouse, despite the fact that they can provide useful information on the macroscopic effects of structural changes in the lung. Although partial PV curves measuring just the changes in lung volume are sometimes reported, without a measure of absolute volume, the nonlinear nature of the total PV curve makes these partial ones very difficult to interpret. In the present study, we describe a standardized way to measure the total PV curve. We have then tested the ability of these curves to detect changes in mouse lung structure in two common lung pathologies, emphysema and fibrosis. Results showed significant changes in several variables consistent with expected structural changes with these pathologies. This measurement of the lung PV curve in mice thus provides a straightforward means to monitor the progression of the pathophysiologic changes over time and the potential effect of therapeutic procedures.

Here we present a protocol to simply and reliably measure the lung pressure-volume curve in mice, showing that it is sufficiently sensitive to detect phenotypic parenchymal changes in two common lung pathologies, pulmonary fibrosis and emphysema. This metric provides a means to quantify the lung&#8217;s structural changes with developing pathology.

La mesure de la courbe pression-volume dans les poumons de souris

In recent decades the mouse has become the primary animal model of a variety of lung diseases. In models of emphysema or fibrosis, the essential ...

Médecine

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

L&#39;imagerie in vivo et des traitements thérapeutiques dans un modèle de souris orthotopique de cancer des ovaires

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Cardiac Catheterization in Mice to Measure the Pressure Volume Relationship: Investigating the Bowditch Effect

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these strategies is to examine their effects on heart function. There are several techniques to measure in vivo cardiac mechanics (e.g., echocardiography, pressure/volume relations, etc.). Compared to echocardiography, real-time left ventricular (LV) pressure/volume analysis via catheterization is more precise and insightful in assessing LV function. Additionally, LV pressure/volume analysis provides the ability to instantaneously record changes during manipulations of contractility (e.g., &#946;-adrenergic stimulation) and pathological insults (e.g., ischemia/reperfusion injury). In addition to the maximum (+dP/dt) and minimum (-dP/dt) rate of pressure change in the LV, an accurate assessment of LV function via several load-independent indexes (e.g., end systolic pressure volume relationship and preload recruitable stroke work) can be attained. Heart rate has a significant effect on LV contractility such that an increase in the heart rate is the primary mechanism to increase cardiac output (i.e., Bowditch effect). Thus, when comparing hemodynamics between experimental groups, it is necessary to have similar heart rates. Furthermore, a hallmark of many cardiomyopathy models is a decrease in contractile reserve (i.e., decreased Bowditch effect). Consequently, vital information can be obtained by determining the effects of increasing heart rate on contractility. Our and others data has demonstrated that the neuronal nitric oxide synthase (NOS1) knockout mouse has decreased contractility. Here we describe the procedure of measuring LV pressure/volume with increasing heart rates using the NOS1 knockout mouse model.

This article describes the measurement of murine left ventricular function via pressure/volume analysis at different heart rates.

Cathétérisme cardiaque chez la souris pour mesurer le volume de pression Relation: Étudier les effets Bowditch

Animal models that mimic human cardiac disorders have been created to test potential therapeutic strategies. A key component to evaluating these ...

Biventricular Assessment of Cardiac Function and Pressure-Volume Loops by Closed-Chest Catheterization in Mice

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) generated by recording both pressure and volume during cardiac catheterization are vital when assessing both systolic and diastolic cardiac function. Left and right heart function are closely related, reflected in ventricular interdependence. Thus, recording biventricular function in the same animal is important to get a complete assessment of cardiac function. In this protocol, a closed chest approach to cardiac catheterization consistent with the way catheterization is performed in patients is adopted in mice. While challenging, the closed chest strategy is a more physiological approach, because opening the chest results in major changes in preload and afterload that create artifacts, most notably a fall in systemic blood pressure. While high-resolution echocardiography is used to assess rodents, cardiac catheterization is invaluable, particularly when assessing diastolic pressures in both ventricles.
Described here is a procedure to perform invasive, closed chest, sequential left and right ventricular pressure-volume (PV) loops in the same animal. PV loops are acquired using&#160;admittance technology with a mouse pressure-volume catheter and pressure-volume system acquisition. The procedure is described, beginning with the neck dissection, which is required to access the right jugular vein and the right carotid artery, to the insertion and positioning of the catheter, and finally the data acquisition. Then, the criteria required to ensure the acquisition of high-quality PV loops are discussed. Finally, the analysis of the left and right ventricular PV loops and the different hemodynamic parameters available to quantify systolic and diastolic ventricular function are briefly described.

Presented here is a protocol to assess biventricular heart function in mice by generating pressure-volume (PV) loops from the right and left ventricle in the same animal using closed chest catheterization. The focus is on the technical aspect of surgery and data acquisition.

Évaluation biventriculaire de la fonction cardiaque et des boucles pression-volume par cathétérisme thoracique fermé chez la souris

Assessment of cardiac function is essential to conduct cardiovascular and pulmonary-vascular preclinical research. Pressure-volume loops (PV loops) ...

Cardiac Response to &#946;-Adrenergic Stimulation Determined by Pressure-Volume Loop Analysis

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of specific treatments on the heart. Due to the feasibility of genetic manipulations the mouse has become the most common mammalian animal model to study cardiac function and to search for new potential therapeutic targets. Here we describe a protocol to determine cardiac function&#160;in vivo using pressure-volume loop measurements and analysis during basal conditions and under &#946;-adrenergic stimulation by intravenous infusion of increasing concentrations of isoproterenol. We provide a refined protocol including ventilation support taking into account the positive end-expiratory pressure to ameliorate negative effects during open-chest measurements, and potent analgesia (Buprenorphine) to avoid uncontrollable myocardial stress evoked by pain during the procedure. All together the detailed description of the procedure and discussion about possible pitfalls enables highly standardized and reproducible pressure-volume loop analysis, reducing the exclusion of animals from the experimental cohort by preventing possible methodological bias.

Here we describe a cardiac pressure-volume loop analysis under increasing doses of intravenously infused isoproterenol to determine the intrinsic cardiac function and the &#946;-adrenergic reserve in mice. We use a modified open-chest approach for the pressure-volume loop measurements, in which we include ventilation with positive end-expiratory pressure.

Réponse cardiaque à la stimulation β-adrénergique déterminée par l’analyse de la boucle pression-volume

Determination of the cardiac function is a robust endpoint analysis in animal models of cardiovascular diseases in order to characterize effects of ...

Cardiac Pressure-Volume Loop Analysis Using Conductance Catheters in Mice

Cardiac pressure-volume loop analysis is the &#8220;gold-standard&#8221; in the assessment of load-dependent and load-independent measures of ventricular systolic and diastolic function. Measures of ventricular contractility and compliance are obtained through examination of cardiac response to changes in afterload and preload. These techniques were originally developed nearly three decades ago to measure cardiac function in large mammals and humans. The application of these analyses to small mammals, such as mice, has been accomplished through the optimization of microsurgical techniques and creation of conductance catheters. Conductance catheters allow for estimation of the blood pool by exploiting the relationship between electrical conductance and volume. When properly performed, these techniques allow for testing of cardiac function in genetic mutant mouse models or in drug treatment studies. The accuracy and precision of these studies are dependent on careful attention to the calibration of instruments, systematic conduct of hemodynamic measurements and data analyses. We will review the methods of conducting pressure-volume loop experiments using a conductance catheter in mice.

Cardiac pressure-volume loop analysis is the most comprehensive way to measure cardiac function in the intact heart. We describe a technique to perform and analyze cardiac pressure volume loops, using conductance catheters.

Cardiac pression-volume Analyse boucle aide de la conductance cathéters chez la souris

Cardiac pressure-volume loop analysis is the &#8220;gold-standard&#8221; in the assessment of load-dependent and load-independent measures of ventricular ...