Nitric oxide synthase 3 (endothelial) (eNOS)

Nitric oxide synthase 3 (eNOS) is a constitutive enzyme primarily expressed in vascular endothelial cells, where it plays a critical role in maintaining cardiovascular homeostasis. It catalyzes the production of nitric oxide (NO), a potent signaling molecule that induces vasodilation, inhibits platelet aggregation, and prevents leukocyte adhesion to the vessel wall (UniProt P29474; PubMed 11418480). Dysregulation or 'uncoupling' of eNOS, where the enzyme produces reactive oxygen species instead of NO, is a hallmark of endothelial dysfunction and contributes significantly to the pathogenesis of atherosclerosis, hypertension, and diabetes (PubMed 15142844). Pharmacological strategies often focus on enhancing eNOS activity or expression through the use of statins, ACE inhibitors, or supplemental cofactors like tetrahydrobiopterin to restore vascular health (StatPearls NBK538315). Conversely, excessive NO production can lead to pathological hypotension, making the precise modulation of this enzyme a key therapeutic challenge.

Other names

Endothelial nitric oxide synthaseNOS3Nitric oxide synthase type IIIConstitutive NOSEC-NOS

Catalyzes the oxidation of L-arginine to L-citrulline and nitric oxide (NO) in the presence of NADPH, oxygen, and cofactors like tetrahydrobiopterin (BH4). NO then activates soluble guanylate cyclase in smooth muscle cells, increasing cGMP and leading to vasodilation.