We want to thank Britta Trautewig, Corinna L&#246;bbert and Ingrid Meder for their commitment.

All animal experiences have been performed according to the guidelines of the local Ethics Animal Review Board of the regional authorities for consumer protection and food safety of Lower Saxony (LAVES, Oldenburg, Germany) with the approval IDs 12/0768 and 17/2472.
1. Heart explantation and perfusion
NOTE: As graft donors, female or male rats at an age of 7-22 weeks were used.
<ol>
	<li>Anesthetize the donor rat by isoflurane inhalation (induction at 5% and mainte...

<ol>
	<li>Abbott, C. P., 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=A+Technique+for+Heart+Transplantation+In+the+Rat.">A Technique for Heart Transplantation In the Rat.</a> Archives of Surgery. 89 (4), 645-652 (1964).</li><li>Tomita, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heart+homotransplantation+in+the+rat.">Heart homotransplantation in the rat.</a> Sapporo igaku zasshi. The Sapporo Medical Journal. 30 (4), 165-183 (1966).</li><li>Ono, K., Lindsey, E. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+technique+of+heart+transplantation+in+rats.">Improved technique of heart transplantation in rats.</a> The Journal of Thoracic and Cardiovascular Surgery. 57 (2), 225-229 (1969).</li><li>Wen, P., 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=A+simple+technique+for+a+new+working+heterotopic+heart+transplantation+model+in+rats.">A simple technique for a new working heterotopic heart transplantation model in rats.</a> Transplantation Proceedings. 45 (6), 2522-2526 (2013).</li><li>Benke, K., 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=Heterotopic+abdominal+rat+heart+transplantation+as+a+model+to+investigate+volume+dependency+of+myocardial+remodeling.">Heterotopic abdominal rat heart transplantation as a model to investigate volume dependency of myocardial remodeling.</a> Transplantation. 101 (3), 498-505 (2017).</li><li>Kearns, M. J., 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=Rat+Heterotopic+Abdominal+Heart/Single-lung+Transplantation+in+a+Volume-loaded+Configuration.">Rat Heterotopic Abdominal Heart/Single-lung Transplantation in a Volume-loaded Configuration.</a> Journal of Visualized Experiments. (99), 52418 (2015).</li><li>Ibrahim, M., 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=Heterotopic+abdominal+heart+transplantation+in+rats+for+functional+studies+of+ventricular+unloading.">Heterotopic abdominal heart transplantation in rats for functional studies of ventricular unloading.</a> The Journal of Surgical Research. 179 (1), e31-e39 (2013).</li><li>Liu, F., Kang, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Heterotopic+heart+transplantation+in+mice.">Heterotopic heart transplantation in mice.</a> Journal of Visualized Experiments. (6), 238 (2007).</li><li>Lu, W., 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=A+new+simplified+volume-loaded+heterotopic+rabbit+heart+transplant+model+with+improved+techniques+and+a+standard+operating+procedure.">A new simplified volume-loaded heterotopic rabbit heart transplant model with improved techniques and a standard operating procedure.</a> Journal of Thoracic Disease. 7 (4), 653-661 (2015).</li><li>Kitahara, H., 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=Heterotopic+transplantation+of+a+decellularized+and+recellularized+whole+porcine+heart.">Heterotopic transplantation of a decellularized and recellularized whole porcine heart.</a> Interactive Cardiovascular and Thoracic Surgery. 22 (5), 571-579 (2016).</li><li>Kadner, A., 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=Heterotopic+heart+transplantation:+experimental+development+and+clinical+experience.">Heterotopic heart transplantation: experimental development and clinical experience.</a> European Journal of Cardiothoracic Surgery. 17 (4), 474-481 (2000).</li><li>Zin&#246;cker, 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=Immune+reconstitution+and+graft-versus-host+reactions+in+rat+models+of+allogeneic+hematopoietic+cell+transplantation.">Immune reconstitution and graft-versus-host reactions in rat models of allogeneic hematopoietic cell transplantation.</a> Frontiers in Immunology. 3 (NOV), 1-12 (2012).</li><li>Klempnauer, J., 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=Genetic+control+of+rat+heart+allograft+rejection:+effect+of+different+MHC+and+non-MHC+incompatibilities.">Genetic control of rat heart allograft rejection: effect of different MHC and non-MHC incompatibilities.</a> Immunogenetics. 30, 81-88 (1989).</li><li>Huang, G., 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=Genetic+manipulations+in+the+rat:+Progress+and+prospects.">Genetic manipulations in the rat: Progress and prospects.</a> Current Opinion in Nephrology and Hypertension. 20 (4), 391-399 (2011).</li><li>Gordon, C. R., 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=Pulse+doppler+and+M-mode+to+assess+viability+of+cardiac+allografts+using+heterotopic+femoral+heart+transplantation+in+rats.">Pulse doppler and M-mode to assess viability of cardiac allografts using heterotopic femoral heart transplantation in rats.</a> Microsurgery. 27 (4), 240-244 (2007).</li><li>Gordon, C. R., 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=A+new+modified+technique+for+heterotopic+femoral+heart+transplantation+in+rats.">A new modified technique for heterotopic femoral heart transplantation in rats.</a> The Journal of Surgical Research. 139 (2), 157-163 (2007).</li><li>Ma, Y., Wang, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+2+heterotopic+heart+transplant+techniques+in+rats:+cervical+and+abdominal+heart.">Comparison of 2 heterotopic heart transplant techniques in rats: cervical and abdominal heart.</a> Experimental and Clinical Transplantation. 9 (2), 128-133 (2011).</li><li>Bektas, H., 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=Differential+effect+of+donor-specific+blood+transfusions+after+kidney,+heart,+pancreas,+and+skin+transplantation+in+major+histocompatibility+complex-incompatible+rats.">Differential effect of donor-specific blood transfusions after kidney, heart, pancreas, and skin transplantation in major histocompatibility complex-incompatible rats.</a> Transfusion. 37 (2), 226-230 (1997).</li><li>Saiho, K. O., 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=Long-term+allograft+acceptance+induced+by+single+dose+anti-leukocyte+common+antigen+(RT7)+antibody+in+the+rat.">Long-term allograft acceptance induced by single dose anti-leukocyte common antigen (RT7) antibody in the rat.</a> Transplantation. 71 (8), 1124-1131 (2001).</li><li>Bektas, H., 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=Blood+transfers+infectious+immunologic+tolerance+in+MHC-incompatible+heart+transplantation+in+rats.">Blood transfers infectious immunologic tolerance in MHC-incompatible heart transplantation in rats.</a> Journal of Heart and Lung Transplantation. 24 (5), 614-617 (2005).</li><li>J&#228;ger, M. D., 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=Sirolimus+promotes+tolerance+for+donor+and+recipient+antigens+after+MHC+class+II+disparate+bone+marrow+transplantation+in+rats.">Sirolimus promotes tolerance for donor and recipient antigens after MHC class II disparate bone marrow transplantation in rats.</a> Experimental Hematology. 35 (1), 164-170 (2007).</li><li>Timrott, K., 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=Application+of+allogeneic+bone+marrow+cells+in+view+of+residual+alloreactivity:+Sirolimus+but+not+cyclosporine+evolves+tolerogenic+properties.">Application of allogeneic bone marrow cells in view of residual alloreactivity: Sirolimus but not cyclosporine evolves tolerogenic properties.</a> PLoS ONE. 10 (4), 1-16 (2015).</li><li>Hadamitzky, M., 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=Memory-updating+abrogates+extinction+of+learned+immunosuppression.">Memory-updating abrogates extinction of learned immunosuppression.</a> Brain, Behavior, and Immunity. 52, 40-48 (2016).</li><li>Beetz, O., 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=Recipient+natural+killer+cells+alter+the+course+of+rejection+of+allogeneic+heart+grafts+in+rats.">Recipient natural killer cells alter the course of rejection of allogeneic heart grafts in rats.</a> Plos One. 14 (8), e0220546 (2019).</li><li>Hirschburger, M., 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=Nicotine+Attenuates+Macrophage+Infiltration+in+Rat+Lung+Allografts.">Nicotine Attenuates Macrophage Infiltration in Rat Lung Allografts.</a> The Journal of Heart and Lung Transplantation. 28 (5), 493-500 (2009).</li><li>Ruzza, A., 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=Heterotopic+heart+transplantation+in+rats:+improved+anesthetic+and+surgical+technique.">Heterotopic heart transplantation in rats: improved anesthetic and surgical technique.</a> Transplantation Proceedings. 42 (9), 3828-3832 (2010).</li><li>Wang, D., 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=A+simplified+technique+for+heart+transplantation+in+rats:+abdominal+vessel+branch-sparing+and+modified+venotomy.">A simplified technique for heart transplantation in rats: abdominal vessel branch-sparing and modified venotomy.</a> Microsurgery. 26 (6), 470-472 (2006).</li><li>Wang, C., 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=A+modified+method+for+heterotopic+mouse+heart+transplantion.">A modified method for heterotopic mouse heart transplantion.</a> Journal of Visualized Experiments. (88), (2014).</li><li>Al-Amran, F. G., Shahkolahi, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Total+arterial+anastomosis+heterotopic+heart+transplantation+model.">Total arterial anastomosis heterotopic heart transplantation model.</a> Transplantation Proceedings. 45 (2), 625-629 (2013).</li><li>Hoerstrup, S. P., 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=Modified+technique+for+heterotopic+rat+heart+transplantation+under+cardioplegic+arrest.">Modified technique for heterotopic rat heart transplantation under cardioplegic arrest.</a> Journal of Investigative Surgery. 13 (2), 73-77 (2000).</li><li>Fry, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Acute+vascular+endothelial+changes+associated+with+increased+blood+velocity+gradients.">Acute vascular endothelial changes associated with increased blood velocity gradients.</a> Circulation Research. 22 (2), 165-197 (1968).</li><li>Ahmadi, A. R., 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=Orthotopic+Rat+Kidney+Transplantation:+A+Novel+and+Simplified+Surgical+Approach.">Orthotopic Rat Kidney Transplantation: A Novel and Simplified Surgical Approach.</a> Journal of Visualized Experiments. (147), (2019).</li><li>Schmid, C., 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=Successful+heterotopic+heart+transplantation+in+rat.">Successful heterotopic heart transplantation in rat.</a> Microsurgery. 15 (4), 279-281 (1994).</li><li>Shan, J., 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=A+modified+technique+for+heterotopic+heart+transplantation+in+rats.">A modified technique for heterotopic heart transplantation in rats.</a> Journal of Surgical Research. 164 (1), 155-161 (2010).</li><li>Moris, D., 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=Mechanisms+of+liver-induced+tolerance.">Mechanisms of liver-induced tolerance.</a> Current Opinion in Organ Transplantation. 22 (1), 71-78 (2017).</li><li>Bickerstaff, A. A., 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=Murine+renal+allografts:+spontaneous+acceptance+is+associated+with+regulated+T+cell-mediated+immunity.">Murine renal allografts: spontaneous acceptance is associated with regulated T cell-mediated immunity.</a> Journal of Immunology. 167 (9), 4821-4827 (2001).</li><li>Mottram, P. L., 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=Electrocardiographic+monitoring+of+cardiac+transplants+in+mice.">Electrocardiographic monitoring of cardiac transplants in mice.</a> Cardiovascular Research. 22 (5), 315-321 (1988).</li><li>Torre-Amione, G., 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=Decreased+expression+of+tumor+necrosis+factor-&#945;+in+failing+human+myocardium+after+mechanical+circulatory+support:+A+potential+mechanism+for+cardiac+recovery.">Decreased expression of tumor necrosis factor-&#945; in failing human myocardium after mechanical circulatory support: A potential mechanism for cardiac recovery.</a> Circulation. 100 (11), 1189-1193 (1999).</li><li>Goldstein, D. J., 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=Circulatory+resuscitation+with+left+ventricular+assist+device+support+reduces+interleukins+6+and+8+levels.">Circulatory resuscitation with left ventricular assist device support reduces interleukins 6 and 8 levels.</a> The Annals of Thoracic Surgery. 63 (4), 971-974 (1997).</li><li>Tang-Quan, K. R., 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=Non-volume-loaded+heart+provides+a+more+relevant+heterotopic+transplantation+model.">Non-volume-loaded heart provides a more relevant heterotopic transplantation model.</a> Transplant Immunology. 23 (1-2), 65-70 (2010).</li><li>Lakhal-Naouar, I., 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=Transcutaneous+immunization+using+SLA+or+rLACK+skews+the+immune+response+towards+a+Th1+profile+but+fails+to+protect+BALB/c+mice+against+a+Leishmania+major+challenge.">Transcutaneous immunization using SLA or rLACK skews the immune response towards a Th1 profile but fails to protect BALB/c mice against a Leishmania major challenge.</a> Vaccine. 37 (3), 516-523 (2019).</li><li>Sousa-Batista, A. 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The authors have nothing to disclose.

The previously described method of heterotopic cardiac transplantation in rats is mainly based on the description of Ono and Lindsey in 19693. Since then, several modifications have been introduced in various species leading to a wide diversity of this model. Combining several of these modifications and introducing our own experience resulting from over 30 years of performing heterotopic heart transplants in the laboratory, we created a feasible surgical approach, which does not require long train...

Heterotopic heart transplantation is a frequently used experimental model for different investigations regarding transplantation tolerance, acute and chronic allograft rejection, ischemia-reperfusion injury, machine perfusion or cardiac remodelling. Among other advantages, the graft function can be monitored noninvasively by palpation and graft failure does not lead to a vital impairment of the recipient in contrast to other organs, such as kidneys or livers.
In 1964, Abbott et al. initially described heterotopic abdominal heart transplantation in rats1. Later, in 1966, the end-to-side technique for anastomoses was described by Tomita et al.2. The groundwork for the currently used model was reported by Ono and Lindsey in 19693. During the last decades, several modifications have been published to create different types of unloaded, partially loaded or loaded left ventricular heart grafts including combined heterotopic heart-lung transplantation4,5,6. For immunological analyses a non-volume loaded heart graft transplantation is most commonly performed. In this case, the blood flow retrogradely enters the donor ascending aorta and subsequently the coronary arteries. The venous drainage occurs along the coronary sinus into the right atrium and ventricle (Figure 1A-B). Therefore, the left ventricle is excluded from blood flow, apart from marginal amounts of blood from Thebesian veins. This also makes it a useful model for studying the pathophysiological mechanisms during left ventricular assist device therapy7.
Heterotopic heart transplantation has been performed in various species including mice, rabbits, pigs and has even been used as a uni- or biventricular assist device in humans8,9,10,11. The rat still represents a popular experimental animal for transplant models, especially since the graft survival times for different rat strain combinations have been well-defined in the past and a large number of immunological reagents are accessible12,13. Unlike mice, rats are larger making surgery and access to lymphatic tissue for immunological analyses more feasible12. Furthermore, the introduction of commercial cloning technologies in rats in recent years will most likely lead to a recurring interest in experimental rat models14.
In general, heterotopic heart grafts can be attached to the recipient vessels either by performing cervical or abdominal anastomosis. However, a few studies suggest that a femoral anastomosis facilitates improved monitoring due to better access for manual palpation or transfemoral echocardiography and thus allows a more precise detection of graft failure15,16.
It has been shown that there is no difference regarding operation time, complication rate, outcome and graft survival time between both anastomosis techniques17. Clearly, the availability of a sufficient number of draining lymph nodes must be mentioned as a benefit of cervical anastomosis; however, longer training periods are required. In contrast, the abdominal anastomosis is less complicated and equally valuable for immunological investigations, especially when combined with results from a novel method of in-ear injection of allogenic cardiac muscle cells and subsequent cervical lymphadenectomy. A combination of both models offers a broad spectrum of post-interventional immunological analyses.
The following protocol refers to operating in pairs of surgeons in order to reduce ischemia time. However, all experiments can be performed by a single person. The setup of instruments and materials for heart explantation and implantation is displayed in Figure 2A-B.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Anesthesia device (including isoflurane vaporizer)</td>
			<td>Summit Anesthesia Solutions</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Cannula (27 G)</td>
			<td>BD Microlance</td>
			<td>302200</td>
			<td></td>
		</tr>
		<tr>
			<td>Carprofen</td>
			<td>Pfizer</td>
			<td>Rimadyl 50 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Cellstar Tubes (15 mL)</td>
			<td>GreinerBioOne</td>
			<td>188271</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell strainer (40 &#181;m)</td>
			<td>BD Falcon</td>
			<td>2271680</td>
			<td></td>
		</tr>
		<tr>
			<td>Collagenase Type CLSII</td>
			<td>Biochrome</td>
			<td>C2-22</td>
			<td></td>
		</tr>
		<tr>
			<td>Compresses 5x5 cm</td>
			<td>Fuhrmann</td>
			<td>31501</td>
			<td></td>
		</tr>
		<tr>
			<td>Compresses 7.5x7.5 cm</td>
			<td>Fuhrmann</td>
			<td>31505</td>
			<td></td>
		</tr>
		<tr>
			<td>Cotton swabs</td>
			<td>Heinz Herenz Medizinalbedarf</td>
			<td>1032128</td>
			<td></td>
		</tr>
		<tr>
			<td>Dexpathenol (5 %)</td>
			<td>Bayer</td>
			<td>&#34;Bepanthen&#34;</td>
			<td></td>
		</tr>
		<tr>
			<td>DPBS BioWhittaker</td>
			<td>Lonza</td>
			<td>17-512F</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>B. Braun</td>
			<td>Aesculap BD557R</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>B. Braun</td>
			<td>Aesculap BD313R</td>
			<td></td>
		</tr>
		<tr>
			<td>Forceps</td>
			<td>B. Braun</td>
			<td>Aesculap BD35</td>
			<td></td>
		</tr>
		<tr>
			<td>Heating mat</td>
			<td>Gaymar Industries</td>
			<td>&#34;T/Pump&#34;</td>
			<td></td>
		</tr>
		<tr>
			<td>Hemostatic gauze</td>
			<td>Ethicon</td>
			<td>Tabotamp</td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin-Natrium 25 000 I.E.</td>
			<td>Ratiopharm</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Isofluran CP</td>
			<td>CP-Pharma</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Large-pored sieve (stainless steel)</td>
			<td>Forschungswerkst&#228;tten Hannover Medical School</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Lidocaine</td>
			<td>Astra Zeneca</td>
			<td>2 % Xylocain</td>
			<td></td>
		</tr>
		<tr>
			<td>Metamizol-Natrium</td>
			<td>Ratiopharma</td>
			<td>Novaminsulfon 500 mg/mL</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro forceps</td>
			<td>B. Braun</td>
			<td>Aesculap BD3361</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro needle holder</td>
			<td>Codman, Johnson &#38; Johnson Medical</td>
			<td>Codmann 80-2003</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro needle holder</td>
			<td>B. Braun</td>
			<td>Aesculap BD336R</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro needle holder</td>
			<td>B. Braun</td>
			<td>Aesculap FD241R</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro scissors</td>
			<td>B. Braun</td>
			<td>Aesculap FD101R</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro scissors</td>
			<td>B. Braun</td>
			<td>Aesculap FM471R</td>
			<td></td>
		</tr>
		<tr>
			<td>Needle holder</td>
			<td>B. Braun</td>
			<td>Aesculap BM221R</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin/Glutamine (100x)</td>
			<td>PAA</td>
			<td>P11-010</td>
			<td></td>
		</tr>
		<tr>
			<td>Peripheral venous catheter (18 G)</td>
			<td>B. Braun</td>
			<td>4268334B</td>
			<td></td>
		</tr>
		<tr>
			<td>Peripheral venous catheter (22 G)</td>
			<td>B. Braun</td>
			<td>4268091B</td>
			<td></td>
		</tr>
		<tr>
			<td>Probe pointed scissors</td>
			<td>B. Braun</td>
			<td>Aesculap BC030R</td>
			<td></td>
		</tr>
		<tr>
			<td>Retractors</td>
			<td>Forschungswerkst&#228;tten Hannover Medical School</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI culture medium</td>
			<td>Lonza</td>
			<td>BE12-702F</td>
			<td></td>
		</tr>
		<tr>
			<td>Saline solution (NaCl 0.9 %)</td>
			<td>Baxter</td>
			<td>No Catalog Number available</td>
			<td></td>
		</tr>
		<tr>
			<td>Scissors</td>
			<td>B. Braun</td>
			<td>Aesculap BC414</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical microscope</td>
			<td>Carl-Zeiss</td>
			<td>OPMI-MDM</td>
			<td></td>
		</tr>
		<tr>
			<td>Sutures (anastomoses)</td>
			<td>Catgut</td>
			<td>Mariderm 8-0 monofil</td>
			<td></td>
		</tr>
		<tr>
			<td>Sutures (ligature)</td>
			<td>Resorba</td>
			<td>Silk 5-0 polyfil</td>
			<td></td>
		</tr>
		<tr>
			<td>Sutures (skin, fascia)</td>
			<td>Ethicon</td>
			<td>Mersilene 3-0</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe (1 mL)</td>
			<td>B. Braun</td>
			<td>9166017V</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe (10 mL)</td>
			<td>B. Braun</td>
			<td>4606108V</td>
			<td></td>
		</tr>
		<tr>
			<td>Syringe (20 mL)</td>
			<td>B. Braun</td>
			<td>4606205V</td>
			<td></td>
		</tr>
		<tr>
			<td>Vascular clamp</td>
			<td>B. Braun</td>
			<td>Aesculap FB708R</td>
			<td></td>
		</tr>
	</tbody>
</table>

an immunological model for heterotopic heart and cardiac muscle cell transplantation in rats

Heterotopic heart transplantation in rats has been a commonly used model for diverse immunological studies for more than 50 years. Several modifications have been reported since the first description in 1964. After 30 years of performing heterotopic heart transplantation in rats, we have developed a simplified surgical approach, which can be easily taught and performed without further surgical training or background.
After dissection of the ascending aorta and the pulmonary artery and ligation of superior and inferior caval and pulmonary veins, the donor heart is harvested and subsequently perfused with ice-cold saline solution supplemented with heparin. After clamping and incising the recipient abdominal vessels, the donor ascending aorta and pulmonary artery are anastomosed to the recipient abdominal aorta and inferior vena cava, respectively, using continuous running sutures.
Depending on different donor-recipient combinations, this model allows analyses of either acute or chronic rejection of allografts. The immunological significance of this model is further enhanced by a novel approach of in-ear injection of vital cardiac muscle cells and subsequent analysis of draining cervical lymphatic tissue.

In the past, different immunological issues have been addressed on the basis of the model, which was validated in the work group by more than 500 transplants with a survival rate of more than 95%13,18,19,20,21,22,23,24. Tota...

Watch this Scientific Journal Video about An Immunological Model for Heterotopic Heart and Cardiac Muscle Cell Transplantation in Rats at JoVE.com

An Immunological Model for Heterotopic Heart and Cardiac Muscle Cell Transplantation in Rats

We describe a model of heterotopic abdominal heart transplantation in rats, implying modifications of current strategies, which lead to a simplified surgical approach. Additionally, we describe a novel rejection model by in-ear injection of vital cardiac muscle cells, allowing further transplant immunological analyses in rats.

Heterotopic heart transplantation in rats has been a commonly used model for diverse immunological studies for more than 50 years. Several modifications ...

Transplant models are valuable tools for immunological research that often require surgical expertise. Here, we present a feasible approach for heterotopic heart and cardiac muscle cell transplantation in rats. By highlighting and simplifying all of the crucial steps of our model, researchers without a surgical background should be able to master this model in a reasonable amount of time.Both transplant models provide valuable insights into the mechanisms of tolerance and rejection and can be applied in various species. We have a lot of experience in teaching this model to individuals without prior surgical training. After learning the crucial steps, we advice patience and sufficient practice with deceased animals.For donor heart explantation, after confirming a lack of response to pedal reflex in anesthetized seven to 22 week old rat donor animal, apply eye lubricant and use mechanical clippers to remove the abdominal and thoracic fur. Place the rat in the supine position on a heating base and fix the limbs at the base of the operation table with elastic bands. Disinfect the exposed skin with 70%ethanol and perform a median laparotomy.Insert retractors into the incision and use sterilized cotton swabs to mobilize the intestine to the left side of the donor to expose the inferior vena cava. Next, puncture the inferior vena cava to allow intravenous injection of 500 International Units of heparin dissolved in one milliliter of ice-cold isotonic saline solution. Stop the bleeding at the punctured site after needle retraction by light compression using a cotton swab.Incise the diaphragm, perform a lateral thoracotomy to both sides of the donor and pin the thorax wall. Remove the pericardium and the vagal nerve by blunt preparation using two micro-needle holders. For exsanguination, transect the abdominal vessels and insert the blunt branch of a probe pointed scissors into the transverse pericardial sinus.Use a compress to dissect the ascending aorta and pulmonary artery as distally as possible under light caudal traction of the heart. Place a single 5-0 ligature around the superior and inferior vena cava and the pulmonary veins and tighten the ligature step-wise as dorsally as possible. Sever the tissue dorsal to the ligature and extract the heart.To perfuse the explanted heart, use an 18 gauge cannula from an intravenous catheter to flush 30 milliliters of ice-cold, isotonic saline solution supplemented with 1000 International Units of heparin through the ascending aorta and the pulmonary artery before placing the heart in a 15 milliliter tube of saline solution on ice. After preparing the 10 to 14 week old recipient rat as just demonstrated, mobilize the intestines to the upper-left side of the recipient onto a warm, wetted compress. And adjust the surgical microscope or a sufficient alternative.After mobilizing the duodenum and proximal jejunum, respectively, using a five to seven full magnification, use cotton swabs and blunt dissection to expose the abdominal aorta and inferior vena cava. Using two micro needle holders to elevate the abdominal vessels without injuring the lumbar veins, place a Cooley vascular clamp onto the vessels. Use a 30 to 45 degree arched 27 gauge cannula to puncture the abdominal vessels.And use Potts scissors to enlarge the puncture site into a longitudinal incision that matches the size of the lumen of the donor vessels. To remove clots and to prevent postoperative thrombosis, perfuse the vessels with saline and place the graft into the situs. Using two simple interrupted 8-0 monofilament non-resorbable sutures, fix the donor ascending aorta to the recipient abdominal aorta at the cranial and caudal corners of the longitudinal incision.To anastomose the ascending aorta of the donor with the abdominal aorta of the recipient place the graft to the right of the recipient vessels while performing the first half of the anastomosis with a running 8-0 monofilament suture. Then place the graft to the left of the recipient vessels and perform the second half of the anastomosis. Fix the donor pulmonary artery to the inferior vena cava in a similar manner with two corner knots at the cranial and caudal corners.After fixing the donor vessel with knots at each corner, place a stitch from the outside to the inside of the vessel to run an intraluminal anastomosis for the first half of the anastomosis. Before tying down the suture, place another stitch from the inside to the outside. To prevent peripheral embolism after finishing the second half of the anastomosis, flush the anastomosis with saline before tightening the knot of the second half of the anastomosis.Place a hemostatic gauze around both anastomoses and carefully release the Cooley vascular clamp to allow graft reperfusion. Managing any bleeding with light compression and sterilized cotton swabs. After about 60 seconds, the heart should start beating.Carefully replace the intestines and close the abdominal fascia and the skin with separate continuous 3-0 polyfilament running sutures. At the appropriate experimental time point, harvest a donor rat heart as demonstrated and use a sterile scalpel or sterile scissors to shred the heart into three by three millimeter fragments. Digest the pieces in 20 milliliters of culture medium supplemented with 0.5 milligrams per milliliter of collagenase for 30 minutes at 37 degree Celsius.At the end of the digestion, add the tissue to a large-pored sieve, while removing the culture medium. Add five to 10 milliliters of isotonic saline solution and strain the tissue slurry through the sieve. And after centrifuging the cell suspension twice, filter it through a 40 micrometer cell strainer.Rinse the strainer with five to 10 milliliters of isotonic saline solution to collect any remaining cells. And after centrifugation, resuspend the isolated rat cardiac cells in saline solution at a concentration of five times 10 to the fifth cells per milliliter. Load a one milliliters syringe with the cell solution and place the anesthetized recipient animal in a lateral position with the target ear facing up.Fix the ear with a finger and double-sided tape, and use a 27 gauge cannula to subcutaneously inject 20 microliters of cardiac muscle cell solution close to the visual capillary vessels into the recipient's ear. After the appropriate experimental observation period, extract the draining cervical lymph nodes and perform the appropriate downstream analyses of interest. Syngenic transplants survived up to 100 days without signs of graft failure.The specific donor-recipient combination can result in different speeds of heterotopic heart transplant rejection. Cryostat sections of the rejected hearts reveal an increase infiltration of immune effector cells, whereas syngenic grafts are largely free of immune cells. Cervical lymphadenectomy and re-stimulation assays of draining lymph node cells after oral cardiac muscle cell injection reveals distinct strain specific immune responses toward heterotopic cardiac tissue in allogenic transplant recipients, warranting further immunological analyses such as cytokine profiling.Handle the vessels carefully when inserting and extracting the needle. Don't put too much attention on the sutures to prevent stenosis. Don't place too many stitches for each anastomosis.

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Research

JoVE Journal

Immunology and Infection

7.4K Views.  Hannover Medical School. I modelli di trapianto sono strumenti preziosi per la ricerca immunologica che spesso richiedono competenze chirurgiche. Qui, presentiamo un approccio fattibile per il trapianto di cellule cardiache e cardiache eterotopiche nei ratti. Evidenziando e semplificando tutti i passaggi cruciali del nostro modello, i ricercatori senza un background chirurgico dovrebbero essere in grado di padroneggiare questo modello in un lasso di tempo ragionevole.Entrambi i modelli di trapianto forniscono ...