Acute effect of burn trauma to small skin areas on myocardial ischemia-reperfusion injury in rat

Introduction: It has been reported that traumas such as transverse abdominal incision before myocardial ischemia result in a significantly decreased infarct size. This phenomenon is named remote preconditioning of trauma. Since small skin burn is one of most common traumas, the effect of this injury on ischemia-induced arrhythmias and infarct size was investigated in a rat model of ischemia-reperfusion injury. Methods: Twenty-four male Wistar rats were randomly assigned to 3 groups. In burn and sham groups, less than 1% of total body surface area of the dorsal skin was exposed to 100 degrees C and 37 degrees C water, respectively. In ischemic preconditioning group, rats were exposed to one cycle of ischemia (5 min) and reperfusion (10 min). Ischemia-reperfusion injury was induced with occlusion and release of left coronary artery for 30 and 120 min, respectively. Infarct size was measured using triphenyl tetrazolium chloride staining and arrhythmias were assessed in accordance with Lambeth conventions. Results: Infarct size was significantly reduced in ischemic preconditioning group compared with the sham group (27 +/- 2% vs. 50 +/- 5%; P < 0.01). Infarct size in the burn group was not significantly reduced. Irreversible ventricular fibrillation was 50% of all ventricular fibrillation in the burn group, while it was 25% in the sham group, however, this difference was not significant. Conclusion: Acute minor coetaneous burn has neither protective nor harmful for the rat myocardial ischemia-reperfusion injury.