Indication For the prevention of angina Pharmacodynamics Nitroglycerin, an organic nitrate, is available in many forms as a vasodilator. Nitroglycerin is used in the treatement of angina pectoris and perioperative hypertension, to produce controlled hypotension during surgical procedures, to treat hypertensive emergencies, and to treat congestive heart failure associated with myocardial infarction. Mechanism of action Similar to other nitrites and organic nitrates, nitroglycerin is converted to nitric oxide (NO), an active intermediate compound which activates the enzyme guanylate cyclase. This stimulates the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP) which then activates a series of protein kinase-dependent phosphorylations in the smooth muscle cells, eventually resulting in the dephosphorylation of the myosin light chain of the smooth muscle fiber. The subsequent release of calcium ions results in the relaxation of the smooth muscle cells and vasodilation.