Background: Neuroprotection during cardiac and aortic arch surgeries has been a topic of extensive concern. Several protocols were developed in the trial to achieve the best neurological outcome; amongst them is nitric oxide (NO) supplementation through extracorporeal membrane oxygenation (ECMO). While NO was shown to influence the neurological outcome when supplemented during cardiac surgeries, a little is known about the cardiac effects. The current study addresses the molecular effects associated with NO supplementation on the myocardium. Methods: Male Sprague Dawley rats (n=20, 450-550gm) were anesthetized and cooled with cardiopulmonary bypass (CPB) to a core temperature of 19±1oC and maintained in hypothermic cardiac arrest for 30 minutes. Then, rats were rewarmed to a target temperature of 35oC for 60 min using CPB without (control group, CPB), or with NO 20 ppm …