Experimental Study On The Relationship Between Nitric Oxide And Classic Ischemic Preconditioning

Due to the rapid increase in the number of the patients with coronary artery disease and the wide performance of complex cardiac surgery, it is urgent to explore the ideal measurement of cardioprotection. After the development in these several years, it is demonstrated that extremly satisfactory clinical effect of cardioprotection scarcely appears during the treatment with the traditional techniques, such as hypothermia and cardioplegia. As a result, the attention and interest of scientists and clinical doctors, recently, has been appealed to a new way in that effective cardioprotection can be achieved by the activation of the endogenous protective function in the body.The discovery of ischemic preconditioning can be regarded as a historical breakthrough in the research of cardioprotection, because the degree of myocardial salvage that could be achieved in this way was the highest ever seen in studies of myocardial protection. Nowdays, it has been attested in a variety of species as well as humans that ischemic preconditioning can confer a remarkable cardioprotection, which involves not only reduction of necrotic myocardial tissue mass, but also acceleration of the recovery of cardiac performance after reperfusion, reduction of reperfusion-induced arrhythmias and improvement of cardiac metabolism. Ischemic preconditioning, however, can be defined a multifactorical pathophysiological process, requiring the interaction of numerous cellular signals, second messengers and effectors.Nitric oxide is an important modulator of biological process, and it plays a key role in regulation of coronary circulation and cardiac contractility function, which implicate it in a wide spectrum of cardiovascular disease. Involvement of NO in late ischemic preconditioning is well established in recent studies suggesting a dual role of NO as a trigger as well as mediator of such protection , but there is a considerable debate regarding the relationship between NO and classic ischemic preconditioning. Our research is aimed at exploring such question. This study consists of three parts:Part One: Experimental observation of the cardioprotection provided by ischemic preconditioningAfter being made into isolated hearts by virtue of Langendorff setting,...