Ein. Protokoll Text <ol><li> Bevor eine Operation, zu betäuben eine männliche Maus (C57BL / 6), 6 Wochen alt oder älter durch Einatmen von 2-5% Isofluran ist. Führen Sie einen Zeh Prise zu bestätigen, dass das Tier ausreichend betäubt ist. </li><li> Die unbewußte Maus auf seiner Rückseite an einem warmen Pad gelegt, um eine konstante Temperatur von 37 ° C zu halten Der präkordiale Brust auf der linken Seite ist rasiert. </li><li> Sichern Sie die Maus auf einer Intubation Gerät mit einem Isofluran gefüllte Kammer. Ein Rohr von 0,2 Innendurchmesser in die Maus die Luftröhre durch Mund, dann den intubierten Maus auf einer aseptischen chirurgischen Bereich (37 ° C mittels eines Temperaturreglers) anschließen und den Endotrachealtubus mit einem Beatmungsgerät (Rate von 120 pro Minute, Druck von 4-6 mm H 2 O); desinfizieren den Bereich mit betadine und 75% Ethanol. </li><li> Bewerben Augensalbe, um die Maus in die Augen. Zeigen Standard-EKG-Elektroden an den Pfoten und schließen Sie die Maus an den EKG-Schreiber. </li&gt; <li> Verwenden einer sterilen Schere, eine 1,5 cm lange Inzision entlang der mittleren Axillarlinie machen. Scheren sind anstatt einem Skalpell verwendet, um eine Verletzung des darunterliegenden Gewebes in Mäusen verhindern. Dann verwenden Sie stumpfe Spitze Gefäß Schere zu sezieren und Einfahren der präkordialen Muskel von der Brustwand. </li><li> Führe eine linksseitige Thorakotomie zwischen dem dritten und vierten Rippen, um die vordere Oberfläche des Herzens und linken Lunge visualisieren </li><li> Weitere einfahren Brustwand mit einem geeigneten Haken, um Visualisierung und Zugänglichkeit zu verbessern. Entfernen Sie den Herzbeutel mit gezahnten Pinzette und stumpfen Schere. </li><li> Ligieren die linke Koronararterie, indem die Nadel (gebunden mit 7-0 Ethilon Nahtmaterial) unterhalb der Arterie mit einem Band von Myokard zwischen der Kapsel und der Arterie. Eine erfolgreiche Okklusion der Koronararterie wird durch Bewegungsmangel / Akinese der vorderen Wand des linken Ventrikels und durch die Veränderungen der EKG-Aufzeichnung (verified zB ST-Strecken-Hebung, QRS broadening) </li><li> Schließen der Brust, indem zwei Maschen (6-0 Ethilon Naht) auf der dritten und vierten Rippe. </li><li> Verwenden Sie 5-0 Ethilon Naht an der Haut zu schließen. </li><li> Für die postoperative Analgesie, verwalten eine einzelne intraperitoneale Injektion von Buprenorphin (0,05 mg / kg). Die Tiere werden spontan innerhalb von 2-5 min zu erholen nach dem Anhalten Isofluran-Narkose. Schließlich legen Sie die Maus in eine warme Käfig und geben 0,6 mg / ml von Buprenorphin im Trinkwasser (Text-Overlay: 0,6 mg / ml in Trinkwasser) bis zur postoperativen Stress zu vermeiden. Überwacht die Maus für den ersten 24 Stunden nach der Operation. </li><li> Echokardiographie durchgeführt wird, um die Herzfunktion von 3 Tagen nach Myokardinfarkt zu bewerten. Erfolgreiche Verfahren wird durch Akinese in der vorderen Wand des linken Ventrikels (siehe beiliegende Video Ergebnisse) verifiziert. Am Ende des Versuchs wird das Herz gesammelt und gelagert werden-80oC für weitere Untersuchungen. Dh Genexpression. </li></ol>

<ol>
	<li>Tabrizchi, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Beta-blocker+therapy+after+acute+myocardial+infarction.">Beta-blocker therapy after acute myocardial infarction.</a> Expert Rev. Cardiovasc. Ther. 11, 293-296 (2013).</li><li>Pell, S., Fayerweather, W. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trends+in+the+incidence+of+myocardial+infarction+and+in+associated+mortality+and+morbidity+in+a+large+employed+population,+1957-1983.">Trends in the incidence of myocardial infarction and in associated mortality and morbidity in a large employed population, 1957-1983.</a> N. Engl. J. Med. 312, 1005-1011 (1985).</li><li>Ramunddal, T., Gizurarson, S., Lorentzon, M., Omerovic, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antiarrhythmic+effects+of+growth+hormone--in+vivo+evidence+from+small-animal+models+of+acute+myocardial+infarction+and+invasive+electrophysiology.">Antiarrhythmic effects of growth hormone--in vivo evidence from small-animal models of acute myocardial infarction and invasive electrophysiology.</a> J. Electrocardiol. 41, 144-151 (2008).</li><li>Thom, T., Haase, N., Rosamond, W., Howard, V. J., Rumsfeld, J., Manolio, T., Zheng, Z. J., Flegal, K., O'Donnell, C., Kittner, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+disease+and+stroke+statistics--2006+update:+A+report+from+the+american+heart+association+statistics+committee+and+stroke+statistics+subcommittee.">Heart disease and stroke statistics--2006 update: A report from the american heart association statistics committee and stroke statistics subcommittee.</a> Circulation. 113, 85-151 (2006).</li><li>van den Bos, E. J., Mees, B. M., de Waard, M. C., de Crom, R., Duncker, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+model+of+cryoinjury-induced+myocardial+infarction+in+the+mouse:+A+comparison+with+coronary+artery+ligation.">A novel model of cryoinjury-induced myocardial infarction in the mouse: A comparison with coronary artery ligation.</a> Am. J. Physiol. Heart Circ. Physiol. 289, 1291-1300 (2005).</li><li>Omerovic, E., Ramunddal, T., Lorentzon, M., Nordlander, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+neuropeptide+y2+receptor+blockade+on+ventricular+arrhythmias+in+rats+with+acute+myocardial+infarction.">Effects of neuropeptide y2 receptor blockade on ventricular arrhythmias in rats with acute myocardial infarction.</a> Eur. J. Pharmacol. 565, 138-143 (2007).</li><li>Ahn, D., Cheng, L., Moon, C., Spurgeon, H., Lakatta, E. G., Talan, M. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+myocardial+infarcts+of+a+predictable+size+and+location+by+branch+pattern+probability-assisted+coronary+ligation+in+c57bl/6+mice.">Induction of myocardial infarcts of a predictable size and location by branch pattern probability-assisted coronary ligation in c57bl/6 mice.</a> Am. J. Physiol. Heart Circ. Physiol. 286, 1201-1207 (2004).</li><li>Lindbom, M., Ramunddal, T., Camejo, G., Waagstein, F., Omerovic, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+effects+of+myocardial+creatine+depletion+on+left+ventricular+function+morphology+and+lipid+metabolism:+Study+in+a+mouse+model.">In vivo effects of myocardial creatine depletion on left ventricular function morphology and lipid metabolism: Study in a mouse model.</a> J. Card Fail. 14, 161-166 (2008).</li><li>Omerovic, E., Bollano, E., Basetti, M., Kujacic, V., Waagstein, L., Hjalmarson, A., Waagstein, F., Soussi, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioenergetic,+functional+and+morphological+consequences+of+postinfarct+cardiac+remodeling+in+the+rat.">Bioenergetic, functional and morphological consequences of postinfarct cardiac remodeling in the rat.</a> J. Mol. Cell. Cardiol. 31, 1685-1695 (1999).</li><li>Gao, E., Lei, Y. H., Shang, X., Huang, Z. M., Zuo, L., Boucher, M., Fan, Q., Chuprun, J. K., Ma, X. L., Koch, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+and+efficient+model+of+coronary+artery+ligation+and+myocardial+infarction+in+the+mouse.">A novel and efficient model of coronary artery ligation and myocardial infarction in the mouse.</a> Circ. Res. 107, 1445-1453 (2010).</li></ol>

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Das chirurgische Verfahren für LCA Ligation wie in diesem Bericht gezeigt, ist eine zuverlässige und reproduzierbare Methode zur Induktion der experimentellen MI bei Mäusen 3, 6. Die Ligation von LCA entsprechend diesem Protokoll induziert Myokardischämie Eingriff typischerweise ~ 40% des linken Ventrikels 3. Dies induziert signifikante EKG-Veränderungen im ST-Segment 7 und sichtbaren Blässe auf der vorderen Oberfläche des Herzens. Aufgrund der großen Myokardinfarkt, können die Mortalität bis zu 30% 8, 9 liegen. Ein Hinweis sollte, dass Infarkt Myokard Bereich und post-MI Sterblichkeit unterschiedlich sein kann zwischen verschiedenen Tierstämmen werden. Das Verfahren hat mehrere Vorteile. Platzierung Hautschnitt entlang mittleren Axillarlinie anstatt auf vorderen Brustwand erleichtert die spätere Untersuchung mit Echokardiographie. Die Maschen in der Operationswunde nicht mit Ultraschallbildgebung der vorderen Segmente des Herzens stören. Darüber hinaus erlaubt die Intubation von Mäusen der Bedienergenügend Zeit, um die Operation durchzuführen. Die Ligation des LCA &quot;in situ&quot; in der Brust ist mehr &quot;physiologische&quot;, wie der Ligation der Ökobilanz nach der Externalisierung der Gegensatz, da dies schwere Bradykardie und globale Hypoxie 10 induziert. Dieser Ansatz gilt auch Vorteile gegenüber der cryoinjury Ansatz als letztere mit pathophysiologischen Prozessen unterscheiden sich von denen der Ischämie-induzierten Herzinfarkt die mechanistische Studien an ischämischer Kardiomyopathie verwechseln kann assoziiert ist. Wir glauben, dass dieses Video und die dazugehörigen Instruktionen werden nützliche Ergänzung zu den bestehenden Techniken für experimentelle MI bei Mäusen sein. Fehlerbehebung: <ol><li> Um die beste Visualisierung wichtige anatomische Strukturen (linke Atrium linken vorderen Ventrikelwand und linken Lunge) zu erhalten, wird die linke Thorakotomie üblicherweise zwischen der dritten und der vierten Rippe ausgeführt. </li><li> Seien Sie sich bewusst, dass versehentliche Punktion der linken atrium führt zu schweren Blutungen, die zum Tod des Tieres führen kann. </li><li> Lungenkontusion sollte vermieden werden, da sie erhöhte Sterblichkeit verursachen können. Wenn linken Lunge deckt das Herz nach dem Öffnen des Brustkorbs, sollte das Lungengewebe vorsichtig mit z. B. Baumwolle-stick eingefahren werden. </li><li> Hohe Konzentration von Isofluran sollte vermieden werden. Typischerweise 2% Isofluran ist optimal für die Erreichung der richtigen Narkose im vorliegenden Chirurgie. </li></ol>

modified technique for coronary artery ligation in mice

Myokardinfarkt (MI) ist eine der wichtigsten Ursachen für Mortalität beim Menschen 1-3. Um die Morbidität und Mortalität bei Patienten mit MI brauchen wir bessere Kenntnisse über Pathophysiologie der Myokardischämie zu verbessern. Dieses Wissen kann wertvoll sein, um neue therapeutische Targets für innovative kardiovaskulären Therapien 4 definieren. Experimentelle MI-Modell bei Mäusen ist eine zunehmend beliebte kleine Tiermodell in der präklinischen Forschung, in der MI durch permanente oder temporäre Unterbindung der linken Koronararterie (LCA) 5 induziert wird. In diesem Video beschreiben wir die Schritt-für-Schritt-Methode, wie experimentelle MI in Mäusen zu induzieren. Das Tier ist erste betäubt mit 2% Isofluran. Die Maus wird dann unbewussten intubiert und mit einem Ventilator zur künstlichen Beatmung. Die linke Brust ist rasiert und 1,5 cm Schnitt entlang mittleren Axillarlinie in der Haut. Die linke großen Brustmuskel ist unverblümt dissociated bis die Rippen freigelegt sind. Die Muskelschichten werden beiseite und zog dann mit einer Augenlid-Retraktor. Nach diesen Vorbereitungen wird linksseitige Thorakotomie zwischen dem dritten und vierten Rippen ausgeführt, um die vordere Oberfläche des Herzens und linken Lunge visualisieren. Das proximale Segment des LCA Arterie wird dann mit einem 7:0 Ethilon Nahtmaterial die typischerweise induziert eine Infarktgröße ~ 40% des linken Ventrikels ligiert. Am Ende wird die Brust geschlossen und die Tiere bekommen postoperative Analgesie (Temgesic, 0,3 mg/50 ml, ip). Die Tiere sind in einem warmen Käfig, bis Spontanheilung gehalten.

<html><table border="1" ><tbody><tr><td> Instrument </td><td> Funktionsbeschreibung </td></tr><tr><td> Blunt-Spitze Schere </td><td> Verwendet, um Haut, Interkostalraum Brustmuskel und Nähte geschnitten </td></tr><tr><td> Eye Retraktor </td><td> Verwendet werden, um chirurgische Exposé </td></tr><tr><td> Blunt-Spitze Pinzette </td><td> Verwendet, um Haut und Muskeln zu begreifen </td></tr><tr><td> Nadelhalter </td><td> Um eine Nadel zu halten </td></tr><tr><td> 5-0 Nahtmaterial </td><td> Verwendet, um Haut nähen </td></tr><tr><td> 6-0 Nahtmaterial </td><td> Verwendet werden, um Brustmuskel vernäht </td></tr><tr><td> 7-0 Nahtmaterial </td><td> Dient zur koronaren ligieren </td></tr></tbody></table> Tabelle 1. Instruments in der Prozedur des Herzinfarktes benutzt. / Ftp_upload/3093/3093figA.jpg &quot;/&gt; Abbildung A. Vor koronare Ligation wurden der linke Vorhof, linke Lunge und vordere Wand des linken Ventrikels ausgesetzt. Die QRS-Komplexe im EKG gezeigt, waren schmal und kurz. <img alt="Abbildung B" src="/files/ftp_upload/3093/3093figB.jpg" /> Abbildung B. Nach koronarer Ligation, die vordere Wand des linken Ventrikels entwickelt Zyanose und diskinesia. Die QRS-Komplexe wurde deutlich breiter und die ST-Segmente waren offensichtlich erhöht, verglichen mit denen, die vor koronaren Ligation.

Watch this Scientific Journal Video about Modified Technique for Coronary Artery Ligation in Mice at JoVE.com

Modified Technique for Coronary Artery Ligation in Mice

Das chirurgische Verfahren zum experimentellen Herzinfarkt in Mäusen zu induzieren beginnt mit linken Thorakotomie zwischen der dritten und der vierten Rippe, um die vordere Oberfläche des Herzens und linken Lunge visualisieren. Die linke Koronararterie ligiert ist, wird die Brust geschlossen und der Maus erlaubt ist, spontan zu erholen.

Geändert Technik für Coronary Artery Ligation in Mäuse

Myocardial infarction (MI) is one of the most important causes of mortality in humans1-3. In order to improve morbidity and mortality in patients with MI ...

modified-technique-for-coronary-artery-ligation-in-mice

Nanyang Technological University

Research

JoVE Journal

Medicine

25.4K Aufrufe.  Sahlgrenska Academy, University of Gothenburg. Das chirurgische Verfahren zum experimentellen Herzinfarkt in Mäusen zu induzieren beginnt mit linken Thorakotomie zwischen der dritten und der vierten Rippe, um die vordere Oberfläche des Herzens und linken Lunge visualisieren. Die linke Koronararterie ligiert ist, wird die Brust geschlossen und der Maus erlaubt ist, spontan zu erholen.

Serie: Modified Technique for Coronary Artery Ligation in Mice

Use of a Hanging Weight System for Coronary Artery Occlusion in Mice

Murine studies of acute injury are an area of intense investigation, as knockout mice for different genes are becoming increasingly available 1-38. Cardioprotection by ischemic preconditioning (IP) remains an area of intense investigation. To further elucidate its molecular basis, the use of knockout mouse studies is particularly important 7, 14, 30, 39. Despite the fact that previous studies have already successfully performed cardiac ischemia and reperfusion in mice, this model is technically very challenging. Particularly, visual identification of the coronary artery, placement of the suture around the vessel and coronary occlusion by tying off the vessel with a supported knot is technically difficult. In addition, re-opening the knot for intermittent reperfusion of the coronary artery during IP without causing surgical trauma adds additional challenge. Moreover, if the knot is not tied down strong enough, inadvertent reperfusion due to imperfect occlusion of the coronary may affect the results. In fact, this can easily occur due to the movement of the beating heart.
Based on potential problems associated with using a knotted coronary occlusion system, we adopted a previously published model of chronic cardiomyopathy based on a hanging weight system for intermittent coronary artery occlusion during IP 39. In fact, coronary artery occlusion can thus be achieved without having to occlude the coronary by a knot. Moreover, reperfusion of the vessel can be easily achieved by supporting the hanging weights which are in a remote localization from cardiac tissues.
We tested this system systematically, including variation of ischemia and reperfusion times, preconditioning regiments, body temperature and genetic backgrounds39. In addition to infarct staining, we tested cardiac troponin I (cTnI)
as a marker of myocardial infarction in this model. In fact, plasma levels of cTnI correlated with infarct sizes (R2=0.8). Finally, we could show in several studies that this technique yields highly reproducible infarct sizes during murine IP and myocardial infarction6, 8, 30, 40, 41. Therefore, this technique may be helpful for researchers who pursue molecular mechanisms involved in cardioprotection by IP using a genetic approach in mice with targeted gene deletion. Further studies on cardiac IP using transgenic mice may consider this technique.

A murine model for myocardial ischemia and ischemic preconditioning is an important tool study cardioprotective mechanisms in vivo. Here, we report an easy applicable in situ model for cardiac IP using a hanging-weight system for coronary artery occlusion.

Die Verwendung eines Hanging Weight System für Okklusion in Mäuse

Murine studies of acute injury are an area of intense investigation, as knockout mice for different genes are becoming increasingly available 1-38. ...

Forschung

Medizin

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

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

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

Koronare Ligation und intramyokardialen Injection in einem Mausmodell der Infarkt

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

The Application Of Permanent Middle Cerebral Artery Ligation in the Mouse

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to develop suitable animal models to study the events that unfold during ischemic insult. These techniques include transient or permanent, focal or global ischemia models using many different animal models, with the most common being rodents.
The permanent MCA ligation method which is also referred as pMCAo in the literature is used extensively as a focal ischemia model in rodents 1-6. This method was originally described for rats by Tamura et al. in 1981 7. In this protocol a craniotomy was used to access the MCA and the proximal regions were occluded by electrocoagulation. The infarcts involve mostly cortical and sometimes striatal regions depending on the location of the occlusion. This technique is now well established and used in many laboratories 8-13. Early use of this technique led to the definition and description of &#x201C;infarct core&#x201D; and &#x201C;penumbra&#x201D; 14-16, and it is often used to evaluate potential neuroprotective compounds 10, 12, 13, 17. Although the initial studies were performed in rats, permanent MCA ligation has been used successfully in mice with slight modifications 18-20 .
This model yields reproducible infarcts and increased post-survival rates. Approximately 80% of the ischemic strokes in humans happen in the MCA area 21 and thus this is a very relevant model for stroke studies. Currently, there is a paucity of effective treatments available to stroke patients, and thus there is a need for good models to test potential pharmacological compounds and evaluate physiological outcomes. This method can also be used for studying intracellular hypoxia response mechanisms in vivo. 
Here, we present the MCA ligation surgery in a C57/BL6 mouse. We describe the pre-surgical preparation, MCA ligation surgery and 2,3,5 Triphenyltetrazolium chloride (TTC) staining for quantification of infarct volumes.

Middle cerebral artery (MCA) ligation is a technique to study focal cerebral ischemia in animal models. In this method, the middle cerebral artery is exposed by craniotomy and ligated by cauterization. This method gives highly reproducible infarct volumes and increased post-operative survival rates compared to other methods available.

Die Anwendung des dauerhaften mittleren Hirnarterie Ligation in der Maus

Focal cerebral ischemia is among the most common type of stroke seen in patients. Due to the clinical significance there has been a prolonged effort to ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study model. As the use of mouse models are often a vital step in preclinical drug discovery and drug development1-8, it is necessary to design a system to introduce drugs into mice in a uniform, reproducible manner. Ideally, the system should permit the collection of blood samples at regular intervals over a set time course. The ability to measure drug concentrations by mass-spectrometry, has allowed investigators to follow the changes in plasma drug levels over time in individual mice1, 9, 10. In this study, paclitaxel was introduced into transgenic mice as a continuous arterial infusion over three hours, while blood samples were simultaneously taken by retro-orbital bleeds at set time points. Carotid artery infusions are a potential alternative to jugular vein infusions, when factors such as mammary tumors or other obstructions make jugular infusions impractical. Using this technique, paclitaxel concentrations in plasma and tissue achieved similar levels as compared to jugular infusion. In this tutorial, we will demonstrate how to successfully catheterize the carotid artery by preparing an optimized catheter for the individual mouse model, then show how to insert and secure the catheter into the mouse carotid artery, thread the end of the catheter out through the back of the mouse&#8217;s neck, and hook the mouse to a pump to deliver a controlled rate of drug influx. Multiple low volume retro-orbital bleeds allow for analysis of plasma drug concentrations over time.

This method was developed with the goal of delivering a steady drug solution via the carotid artery, to assess the pharmacokinetics of novel drugs in mouse models.

Halsschlagader Infusionen für pharmakokinetischen und pharmakodynamischen Analyse von Taxanen in Mäusen

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

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.

Permanent Ligation des linken vorderen absteigenden Koronararterie bei Mäusen: Ein Modell der Post-Myokardinfarkt Umbau und Herzinsuffizienz

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 ...

Ultrasound Based Assessment of Coronary Artery Flow and Coronary Flow Reserve Using the Pressure Overload Model in Mice

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow reserve (CFR) in humans. Reduced CFR is accompanied by marked intramyocardial and pericoronary fibrosis and is used as an indication of the severity of dysfunction. This study explores, step-by-step, the real-time changes measured in the coronary flow velocity, CFR and systolic to diastolic peak velocity (S/D) ratio in the setting of an aortic banding model in mice. By using a Doppler transthoracic imaging technique that yields reproducible and reliable data, the method assesses changes in flow in the septal coronary artery (SCA), for a period of over two weeks in mice, that previously either underwent aortic banding or thoracotomy. 
During imaging, hyperemia in all mice was induced by isoflurane, an anesthetic that increased coronary flow velocity when compared with resting flow. All images were acquired by a single imager. Two ratios, (1) CFR, the ratio between hyperemic and baseline flow velocities, and (2) systolic (S) to diastolic (D) flow were determined, using a proprietary software and by two independent observers. Importantly, the observed changes in coronary flow preceded LV dysfunction as evidenced by normal LV mass and fractional shortening (FS). 
The method was benchmarked against the current gold standard of coronary assessment, histopathology. The latter technique showed clear pathologic changes in the coronary artery in the form of peri-coronary fibrosis that correlated to the flow changes as assessed by echocardiography. 
The study underscores the value of using a non-invasive technique to monitor coronary circulation in mouse hearts. The method minimizes redundant use of research animals and demonstrates that advanced ultrasound-based indices, such as CFR and S/D ratios, can serve as viable diagnostic tools in a variety of investigational protocols including drug studies and the study of genetically modified strains.

Coronary flow reserve (CFR) is useful for assessment of myocardial oxygen demand and evaluation of cardiovascular risk. This study establishes a step-by-step transthoracic Doppler echocardiographic (TTDE) method for longitudinal monitoring of the changes in CFR, as measured from coronary artery in mice, under the experimental pressure overload of aortic banding.

Ultraschall Basierend Beurteilung der koronaren Herzfluss und koronare Flussreserve Mit der Drucküberlastung Modell an der Maus

Transthoracic Doppler echocardiography (TTDE) is a clinically useful, noninvasive tool for studying coronary artery flow velocity and coronary flow ...

Murine Left Anterior Descending (LAD) Coronary Artery Ligation: An Improved and Simplified Model for Myocardial Infarction

Ischemic heart disease (IHD), or acute coronary syndrome (ACS), is one of the leading causes of death in the United States. IHD is characterized by reduced blood supply to the heart, resulting in the loss of oxygen to and the ensuing necrosis of the heart muscle. The MI model has gained popularity for its use as a short-term ischemia-reperfusion model and a long-term permanent ligation model. Below, we describe a reliable method for the permanent ligation of the LAD. With mouse genetic engineering technology becoming more advanced, and with an increasing availability of quality murine surgical instruments, the mouse has become a popular model for MI surgeries. Our surgical model incorporates the use of an easily reversible anesthetic for the rapid recovery of the mouse; a minimally invasive endotracheal intubation without involving a tracheotomy; and a thoracentesis through the original thoracotomy site without creating an additional incision in the chest, as is done in some other methods, to effectively remove excess blood and air from the chest cavity. This method is comparatively less invasive than other methods, which dramatically reduces surgical and post-surgical complications and mortality and improves reproducibility.

Murine Left Anterior Descending LAD Coronary Artery Ligation: An Improved and Simplified Model for Myocardial Infarction

We provide a reliable method for left anterior descending artery (LAD) ligation in a mouse model. This method is comparatively less invasive than other methods, involving endotracheal intubation, a left-sided thoracotomy approach, and thoracentesis. This method can be used as a model for both acute and chronic myocardial infarction (MI).

Murine linken vorderen absteigenden (LAD) Koronararterienligatur: ein verbessertes und vereinfachtes Modell für Myokardinfarkts

Ischemic heart disease (IHD), or acute coronary syndrome (ACS), is one of the leading causes of death in the United States. IHD is characterized by ...

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery (ALCAPA)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly which is one of leading causes of myocardial ischemia and infarction in children. If left untreated, it results in a 90% mortality rate in the first year of life. In patients who survive to the adulthood, the coronary steal phenomenon and retrograde left-sided coronary flow provide a substrate for chronic subendocardial ischemia, which may lead to left ventricular dysfunction, ischemic mitral regurgitation, malignant ventricular arrhythmias, and sudden cardiac death. The average age of life-threatening presentation is 33 years and of sudden cardiac death 31 years. Therefore, surgical correction is highly recommended as soon as the diagnosis is made, regardless of age. In adult-type ALCAPA originating from the right-facing sinus of the pulmonary artery, direct re-implantation of the ALCAPA into the aorta is the more physiologically sound repair technique to re-establish the dual-coronary perfusion system and is recommended. This protocol describes the technique of direct re-implantation of adult-type ALCAPA into the aorta.

Direct Re-implantation of Left Coronary Artery into the Aorta in Adults with Anomalous Origin of Left Coronary Artery from the Pulmonary Artery ALCAPA

Surgical correction of ALCAPA is highly recommended, regardless of age or the degree of intercoronary collateralization. This protocol presents a technique for the direct re-implantation of adult-type ALCAPA into the aorta to re-establish the dual-coronary perfusion. Whenever feasible, direct re-implantation is preferred to other surgical correction techniques.

Direkter Wieder Implantation von linken Koronararterie in die Aorta bei Erwachsenen mit Anomale Ursprung der linken Koronararterie aus der Lungenarterie (ALCAPA)

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital anomaly which is one of leading causes of myocardial ...

Identifying Coronary Artery Calcification on Non-gated Computed Tomography Scans

Coronary artery calcification (CAC) provides an objective measure of coronary artery disease and can readily be identified on non-gated computed tomography (CT) scans with a high correlation with gated cardiac CT scans. This standardized protocol takes a step-wise approach to not only optimizing an image for the identification of calcification but also to distinguishing CAC from other common causes of calcification in the cardiac silhouette. Recognition of CAC on non-gated CT scans helps to identify a very powerful prognostic factor that can influence therapeutic interventions or downstream diagnostic testing without requiring a gated cardiac scan. These non-gated CT scans are often acquired as part of the routine care of the patient, and this data is readily available without another dose of&#160;ionizing radiation. This protocol allows for the precise and accurate extraction of this data for the purposes of retrospective data analysis in clinical research studies, but also in the clinical evaluation and management of patients.

Here, we present a protocol to reliably and systematically identify coronary artery calcification (CAC) on non-gated computed tomography (CT) scans of the chest or abdomen. CAC provides an objective measure of coronary artery disease for both research and clinical purposes.

Identifizierung von koronarer Verkalkungen auf berechnet Tomographie Scans nicht eingezäunt

Coronary artery calcification (CAC) provides an objective measure of coronary artery disease and can readily be identified on non-gated computed ...

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

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

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

Murine Myokardinfarkt Modell mit permanenten Ligation der linken Anterior absteigende Koronararterie

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