Nitric oxide in the failing myocardium.

It is now apparent that NO is produced in the myocardium. There it plays a central role in normal myocardial physiology. In addition, NO has the ability to exert whether beneficial or deleterious effects on the structure and function of the myocardium. At low, "physiologic" concentrations, NO may protect from deleterious stimuli such as mechanical stress and norepinephrine. At higher, "pathologic" concentrations, NO may cause the loss of myocytes. The mechanisms by which NO exerts these contrasting effects may involve decreases and increases in oxidative stress, respectively. A better understanding of the role NO plays in the development and progression of myocardial failure may lead to new treatment strategies.