Les auteurs remercient Christiane Pahrmann pour son aide technique et l&#39;histologie du spectacle.

<html> Souris Balb / C d&#39;un poids minimum de 20g à l&#39;âge de 8 à 12 semaines sont achetés auprès de Charles River (Sandhofer Weg 7, D-97633 Sulzfeld). Les souris sont logées dans des conditions classiques, nourris avec des granulés de souris standard et eau ad libitum. Anesthetize souris avec l&#39;isoflurane (2%) en utilisant une chambre d&#39;induction. <ol><li> Rasez la zone du cou et le côté gauche de la cage thoracique et de désinfecter à l&#39;aide d&#39;éthanol à 80%. </li><li> Placez la souris sur son dos et placer un masque sur sa bouche et le nez pour maintenir l&#39;anesthésie. </li><li> Vérifiez les réflexes pincer la queue et les pattes arrières pour être sûr que la souris est suffisant anesthésiés. </li><li> Sous vue microscopique effectuer une incision médiane cervical séparant la peau, des muscles et du tissu couvrant la trachée. </li><li> Lorsque la trachée est exposé couper un petit trou dans le tissu entre deux anneaux cartouche en dessous de la glotte pour insérer la sonde endotrachéale (figure 1). Insérez la sonde endotrachéale tenant la partie crânienne de la trachée à l&#39;aide de micro forecepts chirurgicale. Vérifiez le mouvement thoracique pour être sûr que les deux poumons sont bien aérés. </li><li> Le taux de respiration (RR) devrait être d&#39;environ 110 par minute, avec une pression inspiratoire de 17 à 18cm H 2 O. Retournez la souris attentivement, couché sur son côté droit, face à son côté gauche. Effectuer une thoracotomie leftsided entre le 3 ème et 4 ème de la côte, et de disséquer les tissus et les muscles soigneusement, en utilisant une Cauter pour prévenir les saignements. </li><li> Ouvrez le thorax attentivement, une fois le thorax est ouvert, trouver le cœur, sans toucher le poumon avec un objet pointu. Maintenant, enlevez la partie du sac péricardique qui recouvre le cœur. </li><li> Le DAL est situé entre l&#39;artère pulmonaire et l&#39;oreillette gauche. Utilisez un 8-0 Prolène suture (Ethicon, Norderstedt, Allemagne) pour ligaturer l&#39;artère interventriculaire antérieure proximale avec une suture simple (figure 2). </li><li> Placer un drain thoracique (28G, un cathéter veineux), entre le 4 ème et 5 ème de la côte. </li><li> Fermer l&#39;incision thoracique en couches, en utilisant 6-0 Prolène sutures course (Ethicon, Norderstedt, Allemagne) pour adapter les côtes et les points de suture Prolène 4-0 fonctionnement (Ethicon, Norderstedt, Allemagne) pour fermer la peau. </li><li> Égoutter le thorax à l&#39;aide d&#39;une seringue 2ml soigneusement (figure 3). Placez la souris sur son dos. Maintenant, prenez la sonde endotrachéale et d&#39;adapter les anneaux cartouche trachéale avec un point unique à l&#39;aide des sutures 7-0 Prolène (Ethicon, Norderstedt, Allemagne). </li><li> Placez le masque sur la souris et fermer la peau à l&#39;aide Prolène 4-0 courir sutures (Ethicon, Norderstedt, Allemagne). </li></ol> Validation Il existe différentes possibilités pour confirmer le succès de la LAD-ligature. Le test de la troponine peut être effectuée 6 à 18 heures après la chirurgie, en utilisant seulement 150 L de sang, sans la nécessité d&#39;euthanasier l&#39;animal. Le sang est appliqué à un kit de test personnalisés troponine (T TROP sensible, Roche, Mannheim) (figure 4). La troponine est une protéine régulatrice dans les filaments d&#39;actine de la cellule musculaire, il ya différents isotypes dans les trois types de muscles. La cTnI et de cTnT isotypes sont trouvés dans le cœur et sont libérés des lésions tissulaires. Le test normalisé pour la troponine T (cTnT) est basé sur deux anticorps monoclonaux spécifiques du cœur, l&#39;un des pièges de la troponine dans l&#39;échantillon de sang, le second est un marqueur. La zone infarcie peut être identifiée macroscopiquement après 3 jours (figure 5). TTC (2,3,5-triphényltétrazolium chlorure) la viabilité des tissus coloration des mesures utilisées pour évaluer la taille d&#39;infarctus. Bleu Evans (1,5%, 1,0 ml) dans un tampon phosphate salin (PBS) est injecté dans la cavité ventriculaire gauche à mesurer la surface du myocarde ischémique. La souris est euthanasié et le cœur est récolté et sectionnés en tranches. Les tranches de tissu sont incubés dans une solution de PBS% TTC, pH 7,4 à 37 ° C pendant 20min. Les tissus sont fixés dans 10% de PBS-formol tamponné nuit à 2-8 ° C. TTC est administré ex vivo pour la teinture bleu Evans-négatif domaines (figure 6). Pour l&#39;histologie de la souris doit être euthanasié et le cœur doit être intégré pour un traitement ultérieur. Après avoir effectué des coupes en paraffine, les lames sont colorées au H &amp; E (hématoxyline-éosine) ou trichrome de visualiser les tissus fibreux (figure 7). <img src="/files/ftp_upload/1438/1438fig1.jpg" alt="Figure 1" /> Figure 1: tube trachéal. 1A: Exposed trachée, après incision cervicale ventrale. 1B: trachée est ouvert deux anneaux cartilagineux caudale au larynx. 1C: tube trachéal est insérée dans la trachée. <img src="/files/ftp_upload/1438/1438fig2.jpg" alt="Figure 2" /> Figure 2: Le coeur est exposée à travers une thoracotomie du côté gauche, le DAL est ligaturé. t &quot;&gt; <img src="/files/ftp_upload/1438/1438fig3.jpg" alt="Figure 3" /> Figure 3: Après le thorax est fermé, un drain pleural est effectué. La souris est toujours sous anesthésie. <img src="/files/ftp_upload/1438/1438fig4.jpg" alt="Figure 4" /> Figure 4: Deux lignes apparaissent après quelques minutes lorsque le test est positif de troponine. <img src="/files/ftp_upload/1438/1438fig5.jpg" alt="Figure 5" /> Figure 5: Affiche le coeur explanté. 5A: Vue macroscopique du cœur avec la zone ischémique avec une couleur fanée blanchâtre. 5B: Coupe transversale du cœur infarci, la zone ischémique montre dans le coin supérieur droit.

<ol>
	<li>Atkins, B. Z., Hueman, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+cardiomyoplasty+improves+diastolic+properties+of+injured+Heart.">Cellular cardiomyoplasty improves diastolic properties of injured Heart.</a> J Surg Res. 85 (2), 234-242 (1999).</li><li>Jaquet, K., KT, K. r. a. u. s. e. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+of+myocardial+scar+size+after+implantation+of+mesenchymal+stem+cells+in+rats:+what+is+the+mechanism.">Reduction of myocardial scar size after implantation of mesenchymal stem cells in rats: what is the mechanism.</a> Stem Cells Dev. 14 (3), 299-309 (2005).</li><li>Joung, B., Kim, I. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bone+marrow+mononuclear+stem+cells+transplanted+in+rat+infarct+myocardium+improved+the+electrical+conduction+without+evidence+of+proarrhythmic+effects.">Bone marrow mononuclear stem cells transplanted in rat infarct myocardium improved the electrical conduction without evidence of proarrhythmic effects.</a> Yonsei Med J. 48 (5), 754-764 (2007).</li></ol>

Financement La présente étude a été soutenue par l&#39;Université de Hambourg Hôpital (MK, Femme Habilitation Grant), DFG (SS, SCHR992/3-1), ISHLT (TD, 2009 Prix de recherche). Déclaration Tous les animaux ont reçu des soins humains en conformité avec les Principes de protection des animaux de laboratoire, des expériences sur les animaux ont été effectuées en conformité avec les directives et règlements établis par la Société nationale pour la recherche médicale et le Guide pour les soins et l&#39;utilisation des animaux de laboratoire publié par le National Institutes of Health (Instituts nationaux de santé de publication 85-23, révisée en 1985). Tous les animaux ont été obtenus à partir de Charles River Laboratories (Sulzfeld, Allemagne) et ont été maintenus dans les installations de soins aux animaux de l&#39;Hôpital universitaire Eppendorf à Hambourg. Les animaux ont reçu la norme chow et eau ad libitum.

En résumé, cette vidéo permet de visualiser le modèle DAL-ligature, étape par étape, et identifie les données DAL-ligature des souris aussi facilement réalisables procédures chirurgicales.

lad-ligation: a murine model of myocardial infarction

Les modèles de recherche de l&#39;infarctus et l&#39;ischémie myocardique sont indispensables pour étudier les processus aigus et chroniques pathobiologiques et physiopathologiques de l&#39;ischémie myocardique et de développer et d&#39;optimiser le traitement futur. Deux méthodes différentes de créer une ischémie myocardique sont effectuées sur des rongeurs de laboratoire. La première méthode est de créer cryo infarctus, une technique rapide mais inexacte, où un cryo-plume est appliqué sur la surface du cœur (1-3). En utilisant cette méthode, le chercheur ne peut garantir que la cryo-cicatriciel entraîne une ischémie, également une blessure vastes du myocarde est créé, qui montre que les effets secondaires physiopathologiques sont pas liés à un infarctus du myocarde. La deuxième méthode est la ligature permanente de l&#39;artère interventriculaire antérieure (AIA). Ici, le DAL est ligaturé avec un point unique, formant une ischémie qui peut être vu presque immédiatement. En fermant la DAL, aucun flux sanguin supplémentaire est permise dans cette zone, tandis que les tissus environnants du myocarde est presque pas affecté. Cette intervention chirurgicale imite les aspects pathobiologiques et physiopathologiques se produisant dans l&#39;infarctus liés à l&#39;ischémie myocardique. La méthode introduite dans cette vidéo démontre la procédure chirurgicale d&#39;un modèle de souris infarctus par ligature de la LAD. Ce modèle est pratique pour les études pathobiologiques et physiopathologiques ainsi que sur les immunobiologiques infarctus du myocarde. La technique montrée offre une grande précision et une bonne corrélation avec les coupes histologiques.

Watch this Scientific Journal Video about LAD-Ligation: A Murine Model of Myocardial Infarction at JoVE.com

LAD-Ligation: A Murine Model of Myocardial Infarction

Cette vidéo montre comment utiliser un modèle rapide et fiable pour étudier les processus pathobiologiques et physiopathologiques de l&#39;ischémie myocardique.

DAL-Ligature: un modèle murin d&#39;infarctus du myocarde

Research models of infarction and myocardial ischemia are essential to investigate the acute and chronic pathobiological and pathophysiological processes ...

lad-ligation-a-murine-model-of-myocardial-infarction

Research

JoVE Journal

Biology

44.4K vues.  University Heart Center Hamburg. Cette vidéo montre comment utiliser un modèle rapide et fiable pour étudier les processus pathobiologiques et physiopathologiques de l'ischémie myocardique.

Vidéo: LAD-Ligation: A Murine Model of Myocardial Infarction

Murine Pancreatic Islet Isolation

Isolement murin îlots pancréatiques

Recherche

Biologie

Murine Model of Hindlimb Ischemia 

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide. Medical therapies for symptomatic relief are limited. Surgical or endovascular interventions are useful for some individuals, but long-term results are often disappointing. As a result, there is a need for developing new therapies to treat PAD. The murine hindlimb ischemia preparation is a model of PAD, and is useful for testing new therapies. When compared to other models of tissue ischemia such as coronary or cerebral artery ligation, femoral artery ligation provides for a simpler model of ischemic tissue. Other advantages of this model are the ease of access to the femoral artery and low mortality rate. 
In this video, we demonstrate the methodology for the murine model of unilateral hindimb ischemia. The specific materials and procedures for creating and evaluating the model will be described, including the assessment of limb perfusion by laser Doppler imaging. This protocol can also be utilized for the transplantation and non-invasive tracking of cells, which is demonstrated by Huang et al.1.

Murine Model of Hindlimb Ischemia

The surgical procedure for induction of unilateral hindlimb ischemia is demonstrated, with confirmation of ischemia by laser Doppler perfusion imaging.

Modèle murin d&#39;ischémie des membres postérieurs

In the United States, peripheral arterial disease (PAD) affects about 10 million individuals, and is also prevalent worldwide.  Medical therapies for ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Murin procédure transplantation rénale

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

Rodent Working Heart Model for the Study of Myocardial Performance and Oxygen Consumption

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways that cannot be accomplished in vivo. For example, inotropic medications commonly also affect preload and afterload, precluding load-independent assessments of their myocardial effects in vivo. Additionally, this model allows for sampling of coronary sinus effluent without contamination from systemic venous return, permitting assessment of myocardial oxygen consumption. Further, the advent of miniaturized pressure-volume catheters has allowed for the precise quantification of markers of both systolic and diastolic performance. We describe a model in which the left ventricle can be studied while performing both volume and pressure work under controlled conditions. 
In this technique, the heart and lungs of a Sprague-Dawley rat (weight 300-500 g) are removed en bloc under general anesthesia. The aorta is dissected free and cannulated for retrograde perfusion with oxygenated Krebs buffer. The pulmonary arteries and veins are ligated and the lungs removed from the preparation. The left atrium is then incised and cannulated using a separate venous cannula, attached to a preload block. Once this is determined to be leak-free, the left heart is loaded and retrograde perfusion stopped, creating the working heart model. The pulmonary artery is incised and cannulated for collection of coronary effluent and determination of myocardial oxygen consumption. A pressure-volume catheter is placed into the left ventricle either retrograde or through apical puncture. If desired, atrial pacing wires can be placed for more precise control of heart rate. This model allows for precise control of preload (using a left atrial pressure block), afterload (using an afterload block), heart rate (using pacing wires) and oxygen tension (using oxygen mixtures within the perfusate).

Isolated working heart models can be used to measure the effect of loading conditions, heart rate, and medications on myocardial performance and oxygen consumption. We describe methods for preparation of a rodent left heart working model that permits study of systolic and diastolic performance and oxygen consumption under various conditions.

Rongeur de travail Modèle de coeur pour l&#39;étude de la performance myocardique et la consommation d&#39;oxygène

Isolated working heart models have been used to understand the effects of loading conditions, heart rate and medications on myocardial performance in ways ...

The Murine Choline-Deficient, Ethionine-Supplemented (CDE) Diet Model of Chronic Liver Injury

Chronic liver diseases, such as viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease, are characterized by continual inflammation, progressive destruction and regeneration of the hepatic parenchyma, liver progenitor cell proliferation, and fibrosis. The end-stage of every chronic liver disease is cirrhosis, a major risk factor for the development of hepatocellular carcinoma. To study processes regulating disease initiation, establishment, and progression, several animal models are used in laboratories. Here we describe a six-week time course of the choline-deficient and ethionine-supplemented (CDE) mouse model, which involves feeding six-week old male C57BL/6J mice with choline-deficient chow and 0.15% DL-ethionine-supplemented drinking water. Monitoring of animal health and a typical body weight loss curve are explained. The protocol demonstrates the gross examination of a CDE-treated liver and blood collection by cardiac puncture for subsequent serum analyses. Next, the liver perfusion technique and collection of different hepatic lobes for standard evaluations are shown, including liver histology assessments by hematoxylin and eosin or Sirius Red stainings, immunofluorescent detection of hepatic cell populations as well as transcriptome profiling of the liver microenvironment. This mouse model is suitable for studying inflammatory, fibrogenic, and liver progenitor cell dynamics induced through chronic liver disease and can be used to test potential therapeutic agents that may modulate these processes.

The Murine Choline-Deficient, Ethionine-Supplemented CDE Diet Model of Chronic Liver Injury

Here we describe a common method to induce chronic liver injury in mice by feeding of a choline-deficient and ethionine-supplemented (CDE) diet. We demonstrate health monitoring, liver perfusion, isolation, and preservation. A time course of six weeks can inform about liver injury, pathohistology, fibrosis, inflammatory, and liver progenitor cell responses.

Le murin déficients en Choline, additionné d’éthionine (CDE) alimentation modèle d’atteinte hépatique chronique

Chronic liver diseases, such as viral hepatitis, alcoholic liver disease, or non-alcoholic fatty liver disease, are characterized by continual ...

A Murine Model of Vertical Sleeve Gastrectomy

Bariatric surgery, such as vertical sleeve gastrectomy (VSG), is a surgery of the gastrointestinal tract that is performed for the purpose of weight loss. Bariatric surgery is currently the most effective long-term treatment for obesity. In addition to weight loss, bariatric surgery produces additional health benefits such as remission of type 2 diabetes, remission of hypertension, and decreased risk of developing certain types of cancer. The mechanisms beyond weight loss for these benefits remain incompletely defined. Therefore, animal models of bariatric surgery are being developed and validated to identify the mechanisms leading to these benefits, with the goal of improving understanding of gastrointestinal physiology and identifying new therapeutic targets. VSG has become the most commonly performed bariatric procedure in the clinic in the United States because it is highly effective at producing weight loss and metabolic improvement, and is simpler to perform than other bariatric procedures. Therefore, we have developed and validated a murine model of VSG. This murine VSG model recapitulates many of the effects of VSG seen in humans, including improved glucose and blood pressure regulation. The method is based on isolation of the stomach, ligation of gastric vessels, and removal of 70% of the stomach by transecting along the greater curvature of the stomach. We have successfully applied this surgical protocol to various genetically modified mouse lines to define the mechanistic contributors to the benefits of VSG. Furthermore, this murine VSG model has been combined with other surgical techniques, to achieve deeper mechanistic insight. Therefore, this is a simple and versatile model for studying gastrointestinal physiology and the health benefits of bariatric surgery.

The following describes the performance of vertical sleeve gastrectomy in mice. This is a type of weight-loss surgery that involves removal of approximately 70% of the stomach.

Un modèle murin de gastrectomie verticale

Bariatric surgery, such as vertical sleeve gastrectomy (VSG), is a surgery of the gastrointestinal tract that is performed for the purpose of weight loss. ...

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer progression. How the chromosomal location and function of a centromere (i.e., centromere identity) are determined and participate in accurate chromosome segregation is a fundamental question. CENP-A is proposed to be the non-DNA indicator (epigenetic mark) of centromere identity, and CENP-A ubiquitylation is required for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability.
Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-CENP-A K124R mutant suggesting that ubiquitylation at a different lysine is induced because of the EYFP tagging in the CENP-A K124R mutant protein. Lysine 306 (K306) ubiquitylation in EYFP-CENP-A K124R was successfully identified, which corresponds to lysine 56 (K56) in CENP-A through mass spectrometry analysis. A caveat is discussed in the use of GFP/EYFP or the tagging of high molecular weight protein as a tool to analyze the function of a protein. Current technical limit is also discussed for the detection of ubiquitylated bands, identification of site-specific ubiquitylation(s), and visualization of ubiquitylation in living cells or a specific single cell during the whole cell cycle.
The method of mass spectrometry analysis presented here can be applied to human CENP-A protein with different tags and other centromere-kinetochore proteins. These combinatory methods consisting of several assays/analyses could be recommended for researchers who are interested in identifying functional roles of ubiquitylation.

Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A EYFP-CENP-A

CENP-A ubiquitylation is an important requirement for CENP-A deposition at the centromere, inherited through dimerization between cell division, and indispensable to cell viability. Here we describe mass spectrometry analysis to identify ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A) protein.

Analyse de spectrométrie de masse pour identifier l’ubiquité de cenp-A marqué par EYFP (EYFP-CENP-A)

Studying the structure and the dynamics of kinetochores and centromeres is important in understanding chromosomal instability (CIN) and cancer ...

A Murine Model of a Burn Wound Reconstructed with an Allogeneic Skin Graft

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and require surgical debridement and skin grafting. Successful integration of the donor graft into a recipient wound bed depends on timely recruitment of immune cells, robust angiogenic response and new extracellular matrix formation. The development of novel therapeutic agents, which target some key processes involved in wound healing, are hindered by the lack of reliable preclinical models with optimized objective assessment of wound closure. Here, we describe an inexpensive and reproducible model of experimental full thickness burn wound reconstructed with an allogeneic skin graft. The wound is induced on the dorsum surface of anaesthetized inbred wild type mice from the BALB/C and SKH1-Hrhr backgrounds. The burn is produced using a brass template measuring 10 mm in diameter, which is preheated to 80 &#176;C and delivered at a constant pressure for 20 s. Burn eschar is excised 24 hours after the injury and replaced with a full thickness graft harvested from the tail of a genetically similar donor mouse. No specialized equipment is required for the procedure and surgical techniques are straightforward to follow. The method may be effortlessly implemented and reproduced in most research settings. Certain limitations are associated with the model. Due to technical difficulties, the harvest of thinner split thickness skin grafts is not possible. The surgical method we describe here allows for the reconstruction of burn wounds using full thickness skin grafts. It may be used to carry out preclinical therapeutic testing.

The aim of this study was to develop a murine model of burn wound healing. A thermal burn was induced on the dorsal skin of mice using a preheated brass template. Burned tissue was debrided and overlaid with a skin graft harvested from the tail of a genetically similar donor mouse.

Un modèle murine d’une blessure de brûlure reconstruite avec une greffe de peau allogénique

Trivial superficial wounds heal without complications by primary intention. Deep wounds, such as full thickness burns, heal by secondary intention and ...

The Establishment of a Murine Mandibular Molar Extraction Socket Healing Model

This study introduces the development of a molar extraction model in the murine mandible to provide a practicable model for studying alveolar bone regeneration and intramembranous ossification. C57/J6 mice were used to extract the mandibular first molar to establish this model. They were euthanized, and the bilateral mandibles harvested, at 1 week and 4 weeks post-surgery, respectively. Subsequent serial stereoscopic harvest, histological assessment, and immunofluorescence staining were performed to demonstrate successful surgery. Immediately after surgery, the stereoscopic images displayed an empty extraction socket. The hematoxylin and eosin (H&#38;E) at 1 week and Masson staining at 4 weeks post-surgery showed that the area of the original root was partially and fully filled with bone trabeculae, respectively. The immunofluorescence staining showed that, compared with the homeostasis side, the Sp7 expression increased at 1 week post-surgery, suggesting vigorous osteogenesis in the alveolar fossa. All these results demonstrated a practicable murine tooth extraction socket healing model. Upcoming studies revealing the mechanisms of jawbone defect healing or socket healing could adopt this method.

This protocol demonstrates step-by-step details of how to extract the mandibular first molar in the mouse. It provides an alternative method for researchers focusing on jawbone healing and regeneration.

L’établissement d’un modèle de guérison par voie d’extraction molaire mandibulaire murine

This study introduces the development of a molar extraction model in the murine mandible to provide a practicable model for studying alveolar bone ...

Explorer les performances cardiaques dépendantes de la FC à l’aide d’un protocole de stimulation auriculaire

A Pacing-Controlled Procedure for the Assessment of Heart Rate-Dependent Diastolic Functions in Murine Heart Failure Models

Heart failure with preserved ejection fraction (HFpEF) is a condition characterized by diastolic dysfunction and exercise intolerance. While exercise-stressed hemodynamic tests or MRI can be used to detect diastolic dysfunction and diagnose HFpEF in humans, such modalities are limited in basic research using mouse models. A treadmill exercise test is commonly used for this purpose in mice, but its results can be influenced by body weight, skeletal muscle strength, and mental state. Here, we describe an atrial-pacing protocol to detect heart rate (HR)-dependent changes in diastolic performance and validate its usefulness in a mouse model of HFpEF. The method involves anesthetizing, intubating, and performing pressure-volume (PV) loop analysis concomitant with atrial pacing. In this work, a conductance catheter was inserted via a left ventricular apical approach, and an atrial pacing catheter was placed in the esophagus. Baseline PV loops were collected before the HR was slowed with ivabradine. PV loops were collected and analyzed at HR increments ranging from 400 bpm to 700 bpm via atrial pacing. Using this protocol, we clearly demonstrated HR-dependent diastolic impairment in a metabolically induced HFpEF model. Both the relaxation time constant (Tau) and the end-diastolic pressure-volume relationship (EDPVR) worsened as the HR increased compared to control mice. In conclusion, this atrial pacing-controlled protocol is useful for detecting HR-dependent cardiac dysfunctions. It provides a new way to study the underlying mechanisms of diastolic dysfunction in HFpEF mouse models and may help develop new treatments for this condition.

Pleins feux sur l’auteur : Étude de la fonction cardiaque dépendante de la FC dans des modèles murins grâce à une nouvelle approche de stimulation auriculaire 

The present protocol describes obtaining the pressure-volume relationship through transesophageal pacing, which serves as a valuable tool in evaluating diastolic function&#160;in mouse models of heart failure.

Procédure contrôlée par la stimulation pour l’évaluation des fonctions diastoliques dépendantes de la fréquence cardiaque dans des modèles murins d’insuffisance cardiaque