Which gas is known as a major pulmonary vasodilator?

Nitric oxide is recognized as a major pulmonary vasodilator because of its unique properties in the cardiovascular system. It plays a critical role in the regulation of vascular tone. Nitric oxide causes the smooth muscle cells in the pulmonary vasculature to relax, leading to the dilation of blood vessels in the lungs. This mechanism significantly improves blood flow and reduces pressure in pulmonary circulation, making it particularly valuable in treating conditions like pulmonary hypertension.

In medical settings, nitric oxide is used therapeutically to improve oxygenation and reduce the workload on the heart, especially in patients with respiratory distress. Its selectivity in targeting the pulmonary vasculature while having minimal systemic effects makes it a preferred option among vasodilators in pulmonary medicine. This characteristic underlines its importance in managing various respiratory and cardiovascular conditions.