Name: real-time digital imaging of leukocyte-endothelial interaction in ischemia-reperfusion injury (iri) of the rat cremaster muscle
Uploaded: 2012-08-05T14:00:00
Description: Watch this Scientific Journal Video about Real-time Digital Imaging of Leukocyte-endothelial Interaction in Ischemia-reperfusion Injury IRI of the Rat Cremaster Muscle at JoVE.com

This work was supported by a grant of the &#x201C;Deutsche Forschungsgemeinschaft&#x201D; to S.U. Eisenhardt (EI 866/1-1).

1. Anesthesia and Monitoring
<ol>
 <li>Appropriate national and institutional ethics should be in place before performing animal experiments. Following approval from the ethics committee anesthetize male Sprague Dawley rats with a body weight from 120 - 180 g. Deliver 2 - 3 vol% isoflurane to a Plexiglas box via isoflurane vaporizer and place the rat inside. </li>
 <li>As soon as the appropriate level of anesthesia is achieved (lack of reaction to toe or tail pinch) the rat is weighted and shaved on the ventral ce...

<ol>
	<li>Cetin, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protective+effect+of+fucoidin+(a+neutrophil+rolling+inhibitor)+on+ischemia+reperfusion+injury:+experimental+study+in+rat+epigastric+island+flaps.">Protective effect of fucoidin (a neutrophil rolling inhibitor) on ischemia reperfusion injury: experimental study in rat epigastric island flaps.</a> Ann. Plast. Surg. 47, 540-546 (2001).</li><li>Granger, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Role+of+xanthine+oxidase+and+granulocytes+in+ischemia-reperfusion+injury.">Role of xanthine oxidase and granulocytes in ischemia-reperfusion injury.</a> Am. J. Physiol. 255, H1269-H1275 (1988).</li><li>Lazarus, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+mast+cells+in+ischaemia-reperfusion+injury+in+murine+skeletal+muscle.">The role of mast cells in ischaemia-reperfusion injury in murine skeletal muscle.</a> J Pathol. 191, 443-448 (2000).</li><li>van den Heuvel, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Review:+Ischaemia-reperfusion+injury+in+flap+surgery.">Review: Ischaemia-reperfusion injury in flap surgery.</a> J. Plast. Reconstr. Aesthet. Surg. 62, 721-726 (2009).</li><li>Rosen, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+surface+lectins+in+the+immune+system.">Cell surface lectins in the immune system.</a> Semin. Immunol. 5, 237-247 (1993).</li><li>van der Flier, A., Sonnenberg, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Function+and+interactions+of+integrins.">Function and interactions of integrins.</a> Cell Tissue Res. 305, 285-298 (2001).</li><li>Panes, J., Perry, M., Granger, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Leukocyte-endothelial+cell+adhesion:+avenues+for+therapeutic+intervention.">Leukocyte-endothelial cell adhesion: avenues for therapeutic intervention.</a> Br. J. Pharmacol. 126, 537-550 (1999).</li><li>Gavins, F. N., Chatterjee, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intravital+microscopy+for+the+study+of+mouse+microcirculation+in+anti-inflammatory+drug+research:+focus+on+the+mesentery+and+cremaster+preparations.">Intravital microscopy for the study of mouse microcirculation in anti-inflammatory drug research: focus on the mesentery and cremaster preparations.</a> J. Pharmacol. Toxicol. Methods. 49, 1-14 (2004).</li><li>Sutton, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Injury+of+the+renal+microvascular+endothelium+alters+barrier+function+after+ischemia.">Injury of the renal microvascular endothelium alters barrier function after ischemia.</a> Am. J. Physiol. Renal. Physiol. 285, 191-198 (2003).</li><li>Serracino-Inglott, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+nitric+oxide+synthase+expression+during+hepatic+ischemia-reperfusion.">Differential nitric oxide synthase expression during hepatic ischemia-reperfusion.</a> Am. J. Surg. 185, 589-595 (2003).</li><li>Eppinger, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mediators+of+ischemia-reperfusion+injury+of+rat+lung.">Mediators of ischemia-reperfusion injury of rat lung.</a> Am J Pathol. 150, 1773-1784 (1997).</li><li>Dumont, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real-time+imaging+of+apoptotic+cell-membrane+changes+at+the+single-cell+level+in+the+beating+murine+heart.">Real-time imaging of apoptotic cell-membrane changes at the single-cell level in the beating murine heart.</a> Nat Med. 7, 1352-1355 (2001).</li><li>Baez, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+open+cremaster+muscle+preparation+for+the+study+of+blood+vessels+by+in+vivo+microscopy.">An open cremaster muscle preparation for the study of blood vessels by in vivo microscopy.</a> Microvasc Res. 5, 384-394 (1973).</li><li>Woeste, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Octreotide+attenuates+impaired+microcirculation+in+postischemic+pancreatitis+when+administered+before+induction+of+ischemia.">Octreotide attenuates impaired microcirculation in postischemic pancreatitis when administered before induction of ischemia.</a> Transplantation. 86, 961-967 (2008).</li><li>Schultz, J. E., Hsu, A. K., Gross, G. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphine+mimics+the+cardioprotective+effect+of+ischemic+preconditioning+via+a+glibenclamide-sensitive+mechanism+in+the+rat+heart.">Morphine mimics the cardioprotective effect of ischemic preconditioning via a glibenclamide-sensitive mechanism in the rat heart.</a> Circ. Res. 78, 1100-1104 (1996).</li><li>Dobschuetz, E. v. o. n. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+intravital+fluorescence+microscopy--a+novel+method+for+the+assessment+of+microvascular+permeability+in+acute+pancreatitis.">Dynamic intravital fluorescence microscopy--a novel method for the assessment of microvascular permeability in acute pancreatitis.</a> Microvasc Res. 67, 55-63 (2004).</li><li>Vutskits, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adverse+effects+of+methylene+blue+on+the+central+nervous+system.">Adverse effects of methylene blue on the central nervous system.</a> Anesthesiology. 108, 684-692 (2008).</li><li>Takasu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+survival+time+with+combined+early+blood+transfusion+and+fluid+administration+in+uncontrolled+hemorrhagic+shock+in+rats.">Improved survival time with combined early blood transfusion and fluid administration in uncontrolled hemorrhagic shock in rats.</a> J. Trauma. 8, 312-316 (2010).</li><li>Proctor, K. G., Busija, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationships+among+arteriolar,+regional,+and+whole+organ+blood+flow+in+cremaster+muscle.">Relationships among arteriolar, regional, and whole organ blood flow in cremaster muscle.</a> Am. J. Physiol. 249, 34-41 (1985).</li><li>Bagher, P., Segal, S. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Mouse+Cremaster+Muscle+Preparation+for+Intravital+Imaging+of+the+Microcirculation.">The Mouse Cremaster Muscle Preparation for Intravital Imaging of the Microcirculation.</a> J. Vis. Exp. (52), e2874 (2011).</li><li>Kanwar, S., Hickey, M. J., Kubes, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Postischemic+inflammation:+a+role+for+mast+cells+in+intestine+but+not+in+skeletal+muscle.">Postischemic inflammation: a role for mast cells in intestine but not in skeletal muscle.</a> Am. J. Physiol. 275, 212-218 (1998).</li><li>Leoni, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inflamed+phenotype+of+the+mesenteric+microcirculation+of+melanocortin+type+3+receptor-null+mice+after+ischemia-reperfusion.">Inflamed phenotype of the mesenteric microcirculation of melanocortin type 3 receptor-null mice after ischemia-reperfusion.</a> FASEB J. 22, 4228-4238 (2008).</li><li>Simoncini, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interaction+of+oestrogen+receptor+with+the+regulatory+subunit+of+phosphatidylinositol-3-OH+kinase.">Interaction of oestrogen receptor with the regulatory subunit of phosphatidylinositol-3-OH kinase.</a> Nature. 407, 538-541 (2000).</li><li>Woollard, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathophysiological+levels+of+soluble+P-selectin+mediate+adhesion+of+leukocytes+to+the+endothelium+through+Mac-1+activation.">Pathophysiological levels of soluble P-selectin mediate adhesion of leukocytes to the endothelium through Mac-1 activation.</a> Circ. Res. 103, 1128-1138 (2008).</li><li>Mori, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ischemia-reperfusion+induced+microvascular+responses+in+LDL-receptor+-/-+mice.">Ischemia-reperfusion induced microvascular responses in LDL-receptor -/- mice.</a> Am. J. Physiol. 276, H1647-H1654 (1999).</li><li>Eisenhardt, S. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+Molecular+Changes+Induced+by+Ischemia/Reperfusion+in+Human+Free+Muscle+Flap+Tissue+Samples.">Monitoring Molecular Changes Induced by Ischemia/Reperfusion in Human Free Muscle Flap Tissue Samples.</a> Ann. Plast. Surg. , (2011).</li><li>Eisenhardt, S. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+activation-specific+human+anti-{alpha}M{beta}2+single-chain+antibodies+as+potential+diagnostic+tools+and+therapeutic+agents.">Generation of activation-specific human anti-{alpha}M{beta}2 single-chain antibodies as potential diagnostic tools and therapeutic agents.</a> Blood. 109, 3521-3528 (2007).</li><li>Eisenhardt, S. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dissociation+of+pentameric+to+monomeric+C-reactive+protein+on+activated+platelets+localizes+inflammation+to+atherosclerotic+plaques.">Dissociation of pentameric to monomeric C-reactive protein on activated platelets localizes inflammation to atherosclerotic plaques.</a> Circ Res. 105, 128-137 (2009).</li><li>Eisenhardt, S. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=C-reactive+protein:+how+conformational+changes+influence+inflammatory+properties.">C-reactive protein: how conformational changes influence inflammatory properties.</a> Cell Cycle. 8, 3885-3892 (2009).</li><li>Granger, D. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Physiology and pathophysiology of leukocyte adhesion. , 520 (1995).</li><li>Baatz, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Kinetics+of+white+blood+cell+staining+by+intravascular+administration+of+rhodamine+6G.">Kinetics of white blood cell staining by intravascular administration of rhodamine 6G.</a> Int. J. Microcirc. Clin. Exp. 15, 85-91 (1995).</li><li>Mempel, T. R. <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+imaging+of+leukocyte+trafficking+in+blood+vessels+and+tissues.">In vivo imaging of leukocyte trafficking in blood vessels and tissues.</a> Curr. Opin. Immunol. 16, 406-417 (2004).</li><li>Abbitt, K. B., Rainger, G. E., Nash, G. B. <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+fluorescent+dyes+on+selectin+and+integrin-mediated+stages+of+adhesion+and+migration+of+flowing+leukocytes.">Effects of fluorescent dyes on selectin and integrin-mediated stages of adhesion and migration of flowing leukocytes.</a> J. Immunol. Methods. 239, 109-119 (2000).</li></ol>

Leukocyte-endothelial interaction, production of reactive oxygen species and activation of the complement system are the key features of IRI-induced tissue dysfunction.26 The microcirculation of the affected tissue is considered as the integral site for the inflammatory onset. Apart from ex vivo experiments such as flow chamber assays27, 28 it is mandatory to provide well-established models of intravital imaging to further evaluate the in vivo relevance. Though IRI has been implica...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the equipment:</td>
 <td>Company:</td>
 <td>Catalogue No.:</td>
 <td>Comments:</td>
 </tr>
 <tr>
 <td>Forene 100% (V/V)</td>
 <td>Abbot</td>
 <td>B506</td>
 <td>API isoflurane</td>
 </tr>
 <tr>
 <td>Terylene Suture</td>
 <td>Serag Weissner</td>
 <td>OC108000</td>
 <td></td>
 </tr>
 <tr>
 <td>Portex Fine Bore Polythene Tubing</td>
 <td>Smiths Medical</td>
 <td>800/100/100</td>
 <td>0.28 mm inner Diameter</td>
 </tr>
 <tr>
 <td>0,9% saline solution</td>
 <td>Fresinus Kabi</td>
 <td>808771</td>
 <td></td>
 </tr>
 <tr>
 <td>Change-A-tip deluxe cautery kit</td>
 <td>Bovie Medical</td>
 <td>DEL1</td>
 <td></td>
 </tr>
 <tr>
 <td>Abbocath -T 14G</td>
 <td>Venisystems</td>
 <td>G713 - A01</td>
 <td>used as lens tube</td>
 </tr>
 <tr>
 <td>Servo Ventilator 900C</td>
 <td>Maquet</td>
 <td></td>
 <td>used as animal ventialtor</td>
 </tr>
 <tr>
 <td>Logical pressure transducer</td>
 <td>Smiths Medical</td>
 <td>MX1960</td>
 <td></td>
 </tr>
 <tr>
 <td>Sirecust 404 Monitor</td>
 <td>Siemens</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>ABL 700 Benchtop Analyzer</td>
 <td>Radiometer</td>
 <td></td>
 <td>for blood gas measurement</td>
 </tr>
 <tr>
 <td>Heating pad</td>
 <td>Effenberger</td>
 <td>8319</td>
 <td></td>
 </tr>
 <tr>
 <td>Aluminum stage</td>
 <td>Alfun</td>
 <td>AW7022</td>
 <td></td>
 </tr>
 <tr>
 <td>Surgical microscope OPMI 6-SDFC</td>
 <td>Carl Zeiss</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>Microsurgical instruments lab set</td>
 <td>S&amp;T</td>
 <td>767</td>
 <td></td>
 </tr>
 <tr>
 <td>Biemer vessel clip</td>
 <td>Diener</td>
 <td>64.562</td>
 <td></td>
 </tr>
 <tr>
 <td>Applying forceps</td>
 <td>Diener</td>
 <td>64.568</td>
 <td>for Biemer vessel clip</td>
 </tr>
 <tr>
 <td>Rhodamine 6G</td>
 <td>Sigma-Aldrich</td>
 <td>R4127</td>
 <td></td>
 </tr>
 <tr>
 <td>Vaseline white DAB</td>
 <td>Winthrop</td>
 <td>2726853</td>
 <td></td>
 </tr>
 <tr>
 <td>Cover glasses</td>
 <td></td>
 <td></td>
 <td>32x32 mm</td>
 </tr>
 <tr>
 <td></td>
 <td></td>
 <td></td>
 <td>Intravital setup</td>
 </tr>
 <tr>
 <td>Zeis Axio Scope A-1 MAT</td>
 <td>Carl Zeis</td>
 <td>490036</td>
 <td>epifluorescence microscope</td>
 </tr>
 <tr>
 <td>470 nm LED</td>
 <td>Carl Zeis</td>
 <td>423052</td>
 <td>fluorescence light source</td>
 </tr>
 <tr>
 <td>Colibri 2 System</td>
 <td>Carl Zeis</td>
 <td>423052</td>
 <td></td>
 </tr>
 <tr>
 <td>W Plan-Apochromat 20x/1,0 DIC</td>
 <td>Carl Zeis</td>
 <td>421452</td>
 <td>water immersion objective</td>
 </tr>
 <tr>
 <td>AxioCam MRm Rev. 3 FireWire</td>
 <td>Carl Zeis</td>
 <td>426509</td>
 <td>high resolution digital camera</td>
 </tr>
 <tr>
 <td>Axio vision LE software</td>
 <td>Carl Zeis</td>
 <td>410130</td>
 <td>use for offline analysis</td>
 </tr>
 </tbody>
</table>

real-time digital imaging of leukocyte-endothelial interaction in ischemia-reperfusion injury (iri) of the rat cremaster muscle

Ischemia-reperfusion injury (IRI) has been implicated in a large array of pathological conditions such as cerebral stroke, myocardial infarction, intestinal ischemia as well as following transplant and cardiovascular surgery.1 Reperfusion of previously ischemic tissue, while essential for the prevention of irreversible tissue injury, elicits excessive inflammation of the affected tissue. Adjacent to the production of reactive oxygen species, activation of the complement system and increased microvascular permeability, the activation of leukocytes is one of the principle actors in the pathological cascade of inflammatory tissue damage during reperfusion.2, 3 Leukocyte activation is a multistep process consisting of rolling, firm adhesion and transmigration and is mediated by a complex interaction between adhesion molecules in response to chemoattractants such as complement factors, chemokines, or platelet-activating factor.4
While leukocyte rolling in postcapillary venules is predominantly mediated by the interaction of selectins5 with their counter ligands, firm adhesion of leukocytes to the endothelium is selectin-controlled via binding to intercellular adhesion molecules (ICAM) and vascular cellular adhesion molecules (VCAM).6, 7 
Gold standard for the in vivo observation of leukocyte-endothelial interaction is the technique of intravital microscopy, first described in 1968.8
Though various models of IRI (ischemia-reperfusion injury) have been described for various organs, 9-12 only few are suitable for direct visualization of leukocyte recruitment in the microvascular bed on a high level of image quality.8 
We here promote the digital intravital epifluorescence microscopy of the postcapillary venule in the cremasteric microcirculation of the rat 13 as a convenient method to qualitatively and quantitatively analyze leukocyte recruitment for IRI-research in striated muscle tissue and provide a detailed manual for accomplishing the technique. We further illustrate common pitfalls and provide useful tips which should enable the reader to truly appreciate, and safely perform the method.
In a step by step protocol we depict how to get started with respiration controlled anesthesia under sufficient monitoring to keep the animal firmly anesthetized for longer periods of time. We then describe the cremasteric preparation as a thin flat sheet for outstanding optical resolution and provide a protocol for leukocyte imaging in IRI that has been well established in our laboratories.

Watch this Scientific Journal Video about Real-time Digital Imaging of Leukocyte-endothelial Interaction in Ischemia-reperfusion Injury IRI of the Rat Cremaster Muscle at JoVE.com

Real-time Digital Imaging of Leukocyte-endothelial Interaction in Ischemia-reperfusion Injury IRI of the Rat Cremaster Muscle

Digital intravital epifluorescence microscopy of postcapillary venules in the cremasteric microcirculation is a convenient method to gain insights into leukocyte-endothelial interaction in vivo in ischemia-reperfusion injury (IRI) of striated muscle tissue. We here provide a detailed protocol to safely perform the technique and discuss its applications and limitations.

Real-time Digital Imaging of Leukocyte-endothelial Interaction in Ischemia-reperfusion Injury (IRI) of the Rat Cremaster Muscle

Ischemia-reperfusion injury (IRI) has been implicated in a large array of pathological conditions such as cerebral stroke, myocardial infarction, ...

real-time-digital-imaging-leukocyte-endothelial-interaction-ischemia

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In situ Transverse Rectus Abdominis Myocutaneous Flap: A Rat Model of Myocutaneous Ischemia Reperfusion Injury

Free tissue transfer is the gold standard of reconstructive surgery to repair complex defects not amenable to local options or those requiring composite tissue. Ischemia reperfusion injury (IRI) is a known cause of partial free flap failure and has no effective treatment. Establishing a laboratory model of this injury can prove costly both financially as larger mammals are conventionally used and in the expertise required by the technical difficulty of these procedures typically requires employing an experienced microsurgeon. This publication and video demonstrate the effective use of a model of IRI in rats which does not require microsurgical expertise. This procedure is an in situ model of a transverse abdominis myocutaneous (TRAM) flap where atraumatic clamps are utilized to reproduce the ischemia-reperfusion injury associated with this surgery. A laser Doppler Imaging (LDI) scanner is employed to assess flap perfusion and the image processing software, Image J to assess percentage area skin survival as a primary outcome measure of injury.

In situ Transverse Rectus Abdominis Myocutaneous Flap: A Rat Model of Myocutaneous Ischemia Reperfusion Injury

Free tissue transfer is widely employed in reconstructive surgery to restore form and function following oncological resection and trauma. Preconditioning this tissue prior to surgery may improve outcome. This article describes an in situ transverse rectus abdominis myocutaneous flap (TRAM) in rats as a means for testing preconditioning strategies.

Free tissue transfer is the gold standard of reconstructive surgery to repair complex defects not amenable to local options or those requiring composite ...

Ischemia-reperfusion Model of Acute Kidney Injury and Post Injury Fibrosis in Mice

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often unreported mortality rates that may confound analyses. Bilateral renal pedicle clamping is commonly used to induce IR-AKI, but differences between effective clamp pressures and/or renal responses to ischemia between kidneys often lead to more variable results. In addition, shorter clamp times are known to induce more variable tubular injury, and while mice undergoing bilateral injury with longer clamp times develop more consistent tubular injury, they often die within the first 3 days after injury due to severe renal insufficiency. To improve post-injury survival and obtain more consistent and predictable results, we have developed two models of unilateral ischemia-reperfusion injury followed by contralateral nephrectomy. Both surgeries are performed using a dorsal approach, reducing surgical stress resulting from ventral laparotomy, commonly used for mouse IR-AKI surgeries. For induction of moderate injury BALB/c mice undergo unilateral clamping of the renal pedicle for 26 min and also undergo simultaneous contralateral nephrectomy. Using this approach, 50-60% of mice develop moderate AKI 24 hr after injury but 90-100% of mice survive. To induce more severe AKI, BALB/c mice undergo renal pedicle clamping for 30 min followed by contralateral nephrectomy 8 days after injury. This allows functional assessment of renal recovery after injury with 90-100% survival. Early post-injury tubular damage as well as post injury fibrosis are highly consistent using this model.

We describe models of moderate and severe ischemia-reperfusion-induced kidney injury in which the mice undergo unilateral renal pedicle clamping followed by simultaneous or delayed contralateral nephrectomy, respectively. These models consistently give rise to renal dysfunction and post-injury fibrosis, but injury severity and survival are dependent on mouse background, age and surgical equipment.

Ischemia-reperfusion induced acute kidney injury (IR-AKI) is widely used as a model of AKI in mice, but results are often quite variable with high, often ...

Induction and Assessment of Ischemia-reperfusion Injury in Langendorff-perfused Rat Hearts

The biochemical events surrounding ischemia reperfusion injury in the acute setting are of great importance to furthering novel treatment options for myocardial infarction and cardiac complications of thoracic surgery. The ability of certain drugs to precondition the myocardium against ischemia reperfusion injury has led to multiple clinical trials, with little success. The isolated heart model allows acute observation of the functional effects of ischemia reperfusion injury in real time, including the effects of various pharmacological interventions administered at any time-point before or within the ischemia-reperfusion injury window. Since brief periods of ischemia can precondition the heart against ischemic injury, in situ aortic cannulation is performed to allow for functional assessment of non-preconditioned myocardium. A saline filled balloon is placed into the left ventricle to allow for real-time measurement of pressure generation. Ischemic injury is simulated by the cessation of perfusion buffer flow, followed by reperfusion. The duration of both ischemia and reperfusion can be modulated to examine biochemical events at any given time-point. Although the Langendorff isolated heart model does not allow for the consideration of systemic events affecting ischemia and reperfusion, it is an excellent model for the examination of acute functional and biochemical events within the window of ischemia reperfusion injury as well as the effect of pharmacological intervention on cardiac pre- and postconditioning. The goal of this protocol is to demonstrate how to perform in situ aortic cannulation and heart excision followed by ischemia/reperfusion injury in the Langendorff model.

The isolated rat heart is an enduring model for ischemia reperfusion injury. Here, we describe the process of harvesting the beating heart from a rat via in situ aortic cannulation, Langendorff perfusion of the heart, simulated ischemia-reperfusion injury, and infarct staining to confirm the extent of ischemic insult.

The biochemical events surrounding ischemia reperfusion injury in the acute setting are of great importance to furthering novel treatment options for ...

Murine Model of Intestinal Ischemia-reperfusion Injury

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, hypotension, necrotizing enterocolitis, bowel transplantation, trauma and chronic inflammation. Intestinal ischemia-reperfusion (IR) injury is a consequence of acute mesenteric ischemia, caused by inadequate blood flow through the mesenteric vessels, resulting in intestinal damage. Reperfusion following ischemia can further exacerbate damage of the intestine. The mechanisms of IR injury are complex and poorly understood. Therefore, experimental small animal models are critical for understanding the pathophysiology of IR injury and the development of novel therapies.
Here we describe a mouse model of acute intestinal IR injury that provides reproducible injury of the small intestine without mortality. This is achieved by inducing ischemia in the region of the distal ileum by temporally occluding the peripheral and terminal collateral branches of the superior mesenteric artery for 60 min using microvascular clips. Reperfusion for 1 hr, or 2 hr after injury results in reproducible injury of the intestine examined by histological analysis. Proper position of the microvascular clips is critical for the procedure. Therefore the video clip provides a detailed visual step-by-step description of this technique. This model of intestinal IR injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Here we describe the detailed procedure of intestinal ischemia-reperfusion in mice which results in reproducible injury without mortality to encourage the standardization of this technique across the field. This model of intestinal ischemia-reperfusion injury can be utilized to study the cellular and molecular mechanisms of injury and regeneration.

Intestinal ischemia is a life-threatening condition associated with a broad range of clinical conditions including atherosclerosis, thrombosis, ...

Inducing Ischemia-reperfusion Injury in the Mouse Ear Skin for Intravital Multiphoton Imaging of Immune Responses

Ischemia-reperfusion injury (IRI) occurs when there is transient hypoxia due to the obstruction of blood flow (ischemia) followed by a subsequent re-oxygenation of the tissues (reperfusion). In the skin, ischemia-reperfusion (IR) is the main contributing factor to the pathophysiology of pressure ulcers. While the cascade of events leading up to the inflammatory response has been well studied, the spatial and temporal responses of the different subsets of immune cells to an IR injury are not well understood. Existing models of IR using the clamping technique on the skin flank are highly invasive and unsuitable for studying immune responses to injury, while similar non-invasive magnet clamping studies in the skin flank are less-than-ideal for intravital imaging studies. In this protocol, we describe a robust model of non-invasive IR developed on mouse ear skin, where we aim to visualize in real-time the cellular response of immune cells after reperfusion via multiphoton intravital imaging (MP-IVM).

This protocol describes the induction of an ischemia-reperfusion (IR) model on mouse ear skin using magnet clamping. Using a custom-built intravital imaging model, we study in vivo inflammatory responses post-reperfusion. The rationale behind the development of this technique is to extend the understanding of how leukocytes respond to skin IR injury.

Ischemia-reperfusion injury (IRI) occurs when there is transient hypoxia due to the obstruction of blood flow (ischemia) followed by a subsequent ...

Evaluation of Coronary Flow Reserve After Myocardial Ischemia Reperfusion in Rats

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via recanalization of the coronary artery is the most effective strategy for reducing the size of ischemic myocardium. The coronary microvasculature cannot be visualized and imaged&#160;in vivo, but there are several invasive and noninvasive techniques that can be used to assess parameters which depend directly on coronary microvascular function. The endothelial function after ischemia reperfusion can be assessed also at the level of the coronary circulation via the coronary flow reserve (CFR).&#160;In this study, peak velocity of left anterior descending (LAD) coronary arteries was measured in rats in vivo via Transthoracic Doppler Echocardiography during resting and stress challenge (induced by Dobutamine). A normal heart can increase its coronary blood flow up to four times above the resting values during stress induction. Following ischemia reperfusion, we found a significantly diminished CFR, which can be used as a marker of coronary microvascular dysfunction. CFR has opened a window on the importance of microvascular dysfunction and has been shown to predict cardiovascular risk independent of whether the severe obstructive disease is present.

Coronary flow reserve (CFR), is defined as the ratio of maximal coronary blood flow to the resting coronary blood flow. We present a protocol for evaluating CFR in rats via ultrasound, which offers the opportunity to predict cardiovascular risk factors in the absence of obstructive coronary disease.

Coronary artery disease is the leading cause of death worldwide. After an acute myocardial infarction, early and successful myocardial intervention via ...

A Pre-clinical Rat Model for the Study of Ischemia-reperfusion Injury in Reconstructive Microsurgery

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many areas of biomedical research due to its cost-effectiveness and its translation to humans. This protocol describes a method to create a preclinical free skin flap model in rats with ischemia-reperfusion injury. The described 3 cm x 6 cm rat free skin flap model is easily obtained after the placement of several vascular ligatures and the section of the vascular pedicle. Then, 8 h after the ischemic insult and completion of the microsurgical anastomosis, the free skin flap develops the tissue damage. These ischemia-reperfusion injury-related damages can be studied in this model, making it a suitable model for evaluating therapeutic agents to address this pathophysiological process. Furthermore, two main monitoring techniques are described in the protocol for the assessment of this animal model: transit-time ultrasound technology and laser speckle contrast analysis.

Here, we describe a pre-clinical animal model for studying the pathophysiology of ischemia-reperfusion injury in reconstructive microsurgery. This free skin flap model based on the superficial caudal epigastric vessels in the rat may also allow for the evaluation of different therapies and compounds to counteract ischemia-reperfusion injury-related damage.

Ischemia-reperfusion injury is the main cause of flap failure in reconstructive microsurgery. The rat is the preferred preclinical animal model in many ...

Delayed Intramyocardial Delivery of Stem Cells after Ischemia Reperfusion Injury in a Murine Model

There is significant interest in the use of stem cells (SCs) for the recovery of cardiac function in individuals with myocardial injuries. Most commonly, cardiac stem cell therapy is studied by delivering SCs concurrently with the induction of myocardial injury. However, this approach presents two significant limitations: the early hostile pro-inflammatory ischemic environment may affect the survival of transplanted SCs, and it does not represent the subacute infarction scenario where SCs will likely be used. Here we describe a two-part series of surgical procedures for the induction of ischemia-reperfusion injury and delivery of mesenchymal stem cells (MSCs). This method of stem cell administration may allow for the longer viability and retention around damaged tissue by circumventing the initial immune response. A model of ischemia reperfusion injury was induced in mice accompanied by the delivery of mesenchymal stem cells (3.0 x 105), stably expressing the reporter gene firefly luciferase under the constitutively expressed CMV promoter, intramyocardially 7 days later. The animals were imaged via ultrasound and bioluminescent imaging for confirmation of injury and injection of cells, respectively. Importantly, there was no added complication rate when performing this two-procedure approach for SC delivery. This method of stem cell administration, collectively with the utilization of state-of-the-art reporter genes, may allow for the in vivo study of viability and retention of transplanted SCs in a situation of chronic ischemia commonly seen clinically, while also circumventing the initial pro-inflammatory response. In summary, we established a protocol for the delayed delivery of stem cells into the myocardium, which can be used as a potential new approach in promoting regeneration of the damaged tissue.

Stems cells are continuously investigated as potential treatments for individuals with myocardial damage, however, their decreased viability and retention within injured tissue can impact their long-term efficacy. In this manuscript we describe an alternative method for stem cell delivery in a murine model of ischemia reperfusion injury.

There is significant interest in the use of stem cells (SCs) for the recovery of cardiac function in individuals with myocardial injuries. Most commonly, ...

Organ Ischemia-Reperfusion Injury by Simulating Hemodynamic Changes in Rat Liver Transplant Model

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, including ischemia-reperfusion injury (IRI) of extrahepatic organs. This model requires numerous experiments and devices. The duration of anhepatic phase is closely related to the time to develop IRI after transplantation. In this experiment, we used hemodynamic changes to induce extrahepatic organ damage in rats and determined the maximum tolerance time. The time until the most severe organ injury varied for different organs. This method can easily be replicated and can also be used to study IRI of the extrahepatic organs after liver transplantation.

This paper provides a detailed description of how to build an animal model of the anhepatic phase (liver ischemia) in rats to facilitate basic research into ischemia-reperfusion injury after liver transplantation.

Orthotopic liver transplantation (OLT) in rats is a tried and proven animal model used for preoperative, intraoperative, and postoperative studies, ...

Real-Time Assessment of Spinal Cord Microperfusion in a Porcine Model of Ischemia/Reperfusion

Spinal cord injury is a devastating complication of aortic repair. Despite developments for the prevention and treatment of spinal cord injury, its incidence is still considerably high and therefore, influences patient outcome. Microcirculation plays a key role in tissue perfusion and oxygen supply and is often dissociated from macrohemodynamics. Thus, direct evaluation of spinal cord microcirculation is essential for the development of microcirculation-targeted therapies and the evaluation of existing approaches in regard to spinal cord microcirculation. However, most of the methods do not provide real-time assessment of spinal cord microcirculation. The aim of this study is to describe a standardized protocol for real-time spinal cord microcirculatory evaluation using laser-Doppler needle probes directly inserted in the spinal cord. We used a porcine model of ischemia/reperfusion to induce deterioration of the spinal cord microcirculation. In addition, a fluorescent microsphere injection technique was used. Initially, animals were anesthetized and mechanically ventilated. Thereafter, laser-Doppler needle probe insertion was performed, followed by the placement of cerebrospinal fluid drainage. A median sternotomy was performed for exposure of the descending aorta to perform aortic cross-clamping. Ischemia/reperfusion was induced by supra-celiac aortic cross-clamping for a total of 48 min, followed by reperfusion and hemodynamic stabilization. Laser-Doppler Flux was performed in parallel with macrohemodynamic evaluation. In addition, automated cerebrospinal fluid drainage was used to maintain a stable cerebrospinal pressure. After completion of the protocol, animals were sacrificed, and the spinal cord was harvested for histopathological and microsphere analysis. The protocol reveals the feasibility of spinal cord microperfusion measurements using laser-Doppler probes and shows a marked decrease during ischemia as well as recovery after reperfusion. Results showed comparable behavior to fluorescent microsphere evaluation. In conclusion, this new protocol might provide a useful large animal model for future studies using real-time spinal cord microperfusion assessment in ischemia/reperfusion conditions.

Spinal cord microcirculation plays a pivotal role in spinal cord injury. Most methods do not allow real-time assessment of spinal cord microcirculation, which is essential for the development of microcirculation-targeted therapies. Here, we propose a protocol using Laser-Doppler-Flow Needle probes in a large animal model of ischemia/reperfusion.

Spinal cord injury is a devastating complication of aortic repair. Despite developments for the prevention and treatment of spinal cord injury, its ...