Preconditioning With Ozone Abrogates Acute Rejection and Prolongs Cardiac Allograft Survival in Rats

Abstract Acute cardiac allograft rejection remains a major cause of morbidity and mortality after heart transplantation and predisposes for the development of graft vasculopathy. The aim of this study was to investigate the immunomodulatory effect of preconditioning of the donor and recipient with medical ozone (O 3 /O 2 ) on acute allograft rejection. Minimizing the initial ischemia-reperfusion injury may result in a reduction of graft vasculopathy and ameliorate long-term outcomes after cardiac transplantation. Lewis rats were challenged with Wistar-Furth cardiac allograft. In donor and recipient animals a medical ozone (O 3 /O 2 )-pneumoperitoneum was induced by single (1×) or repetitive (5×) insufflation (concentration: 50 μg/mL, 80 mL/kg body weight) of medical ozone intraperitoneally. Without immunomodulatory therapy (n = 11) cardiac allograft survival was 5.9 ± 0.9 days. Preconditioning with medical ozone alone (single bolus as well as repetitive administration, n = 7) of the donor and recipient animals prolonged cardiac allograft survival significantly to 7.6 ± 1.4 days ( P