Study Of Endothelial Dependent Relaxation And Non-endothelial Dependent Relaxation Of Porcine Coronary Artery

Objectives:Coronary artery disease (CAD) is a common disease, due to living standard improvement and social environment changes , disease incidence increases constantly. At present, therapeutic methods mainly are drug treatment and operation. Operative treatments primarily include coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA), which are effective methods in treating CAD. However, it is difficult to operate on patients, which occur in small vessels in diameter and (or) coronary artery diffuse diseases.Ischemia generally has been assumed to cause maximal vasodilation of the coronary microvasculature and to render these vessels unresponsive to vasoactive factors stimuli. However, recent studies have demonstrated that even during ischemia, the coronary resistance vessels often retain some degree of vasomotor tone and can respond to vasodilators stimuli to cause vasodilatation of the microvasculature (arteriole and micro-artery), especially in arteriole. Therefore, it provides a theoretical basis of drug treatment for CAD. But in clinical situations in which myocardial ischemia results from a flow-limiting coronary artery stenosis (the extent to stenosis is more than 70%).Non-selective pharmacologic vasodilatation of the coronary microvasculature could worsen ischemia.However, at present, most of the studies of myocardial perfusion regulation focus on arteriole and micro-arteriole, less focus on epicardial artery. For this reason, the objects of this study were the proximal part, the middle part and the distal part of...