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

Summary

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.

Abstract

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.

Introduction

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 d....

Protocol

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.

1. Anesthetize the donor rat by isoflurane inhalation (induction at 5% and maintenance at 3% with an O₂ flow of 1 L/min). Inject 5 mg of Carprofen subcutaneously per kg of bodyweight for perioperative analgesia and check....

Results

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.......

Discussion

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.......

Materials

List of materials used in this article

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