Singlet oxygen energy illumination during moderate cold ischemia prolongs the survival of concordant hamster xeno-heart transplants.
BACKGROUND
Singlet oxygen energy (SOE) is a potent inhibitor of reactive oxygen species (ROS) in vitro and in vivo in certain dose ranges and can improve the levels of high-energy phosphates (HEP) in concordant hamster xeno-heart transplants. Some data indicate that a certain degree of cold ischemia (CI) might be beneficial to xenotransplants. We investigated if SOE illumination of hamster xeno-hearts during moderate cold ischemia (CI) improved graft survival.


METHODS
Eighteen hearts from Golden Syrian hamsters (70 to 80 g) were subjected to 8 hours of CI in cold (+4 degrees C) saline solution (NaCL, 0.9%) before heterotopic cervical transplantation to Lewis rats (220 g). Among the treatment group (n = 8), SOE was produced by illuminating the hearts for 10 minutes every 30 minutes with photons at lambda 634 nm with the Oxylight equipment. Graft function was evaluated every 6 hours after transplantation with digital exam until cessation of heart beats.


RESULTS
The graft survival of SOE-illuminated ischemic hamster xenografts was 2.34 +/- 0.56 versus 1.15 +/- 0.37 days in the control group (P < .05). All hearts displayed immediate graft function versus 70% in the controls (NS).


CONCLUSIONS
SOE illumination at lambda 634 nm during moderate cold ischemia (+4 degrees C) can improve the survival of concordant hamster xeno-heart transplants. The exact mechanism(s) are currently unknown, but the effect might in part be exerted by a combination of reduced production of ROS and increased oxidative phosphorylation.
Lukes
D J
DJ
Department of Surgery and Transplantation, Wallenberg Laboratory for Cardiovascular Research, Göteborg, Sweden.
Skogsberg
U
U
Nilsson
A
A
Lundgren
A
A
Olausson
M
M
Soussi
B
B
D000818:Animals; D006224:Cricetinae; D006085:Graft Survival / Q000276:immunology*; D016027:Heart Transplantation / Q000276:immunology*; D007511:Ischemia; D008297:Male; D017202:Myocardial Ischemia; D051381:Rats; D011917:Rats, Inbred Lew; D017382:Reactive Oxygen Species / Q000378:metabolism; D026082:Singlet Oxygen / Q000378:metabolism*; D014183:Transplantation, Heterologous / Q000276:immunology*
D017382:Reactive Oxygen Species; D026082:Singlet Oxygen