What is the Origin of Nitric Oxide Vasodilation?

The term combines nitric oxide, the specific molecule, with vasodilation, derived from the Latin vas (vessel) and dilatare (to spread out). The discovery of nitric oxide's role as an endothelium-derived relaxing factor (EDRF) was a major scientific breakthrough in the late 20th century, earning a Nobel Prize and revolutionizing cardiovascular pharmacology.

What is the Mechanism of Nitric Oxide Vasodilation?

Nitric oxide is synthesized from the amino acid L-arginine by the enzyme nitric oxide synthase (NOS) in the endothelial cells. Once produced, NO rapidly diffuses into the adjacent smooth muscle cells, where it activates the enzyme soluble guanylate cyclase (sGC). This activation increases the intracellular concentration of cyclic guanosine monophosphate (cGMP), which ultimately triggers the cascade that causes the muscle cells to relax, resulting in vessel widening and reduced vascular resistance.

Nitric Oxide Vasodilation

Meaning

The critical physiological process by which the gaseous signaling molecule nitric oxide (NO) induces the relaxation of vascular smooth muscle cells, leading to an increase in the diameter of blood vessels, a phenomenon known as vasodilation. This essential mechanism is mediated by endothelial cells lining the blood vessels and plays a central role in regulating blood pressure, tissue perfusion, and cardiovascular health. Endocrine factors, such as estrogen and testosterone, significantly influence the production and bioavailability of nitric oxide.