Abstract

Endothelium-derived nitric oxide (NO) is a powerful pulmonary vasodilator which also prevents adhesion and aggregation of platelets, controls growth of smooth muscle, and influences the expression of growth promoting and vasoactive substances. Impaired endothelial NO production contributes to pulmonary vasoconstriction and vascular remodelling in several forms of pulmonary hypertension. Exogenous NO gas delivered via the airspaces is a selective pulmonary vasodilator now used as treatment in various lung disorders.