Apoptosis amelioration through hypothermic reperfusion in heart transplant

OBJECTIVE: To investigate the effects of two different sets of graft temperature during perfusion on myocardial protection in the immediate post transplantation period in rats. MATERIALS AND METHODS: Rats grouped into: Sham and two study groups, which include two set groups of heterotopic heart transplant perfused at two different temperature set. The studied groups underwent cuff method cervical heterotopic heart transplant. Myocardial cell injury and stress were assessed by measuring: Cardiac troponin-I, score of tissue injury, reactive oxygen species (ROS) and nitrogen, caspase 3 enzyme, and degree of myocardial apoptosis. The low set temperature (18°C) significantly reduced myocardial cell injury compared to 37°C reperfusion temperature. This cytoprotective effect of low temperature reperfusion phase was addressed by significant reduction in ROS and nitrogen and inflammatory cytokines, caspase 3, and myocardial apoptosis. CONCLUSION: Hypothermic reperfusion phase exerts cytoprotection in heart transplant through down regulation of oxygen, nitrogen reactive species, and inhibition of apoptosis.