The role of nitric oxide in the cardiovascular response to physical training

Introduction. In 1980 Furchgort and Zawadzki [1] showed that the vascular endothelium is capable of releasing a potent short-acting vasodilating substance in response to the application of acetylcholine (ACh). This substance, initially defined as endothelium-derived relaxing factor, was subsequently identified with nitric oxide (NO) [2]. Since then a wealth of research has demonstrated the involvement of this molecule not only in the regulation of vascular resistance but also in immunological processes, neuronal transmission, platelet function, growth of smooth muscle cells and cardiac mechanical and electrophysiological properties [3-5].