The Mechanism of Action of Nitrates at the Cellular Level
Nitrates are considered “direct-acting” vasodilators. Their effect is not mediated by a neurohumoral mechanism involving the adrenergic system, the renin-angio- tensin system or other vasodilatory mechanisms. Although it has been suggested that some of the dilatory effect of nitrates is exerted by the release of vasodilating prostaglandins, most investigators believe that this is not the main mechanism of action. Thus it is generally accepted that nitrates act directly, at the cellular level, in vascular smooth muscle.