Vascular smooth muscle and endothelial vasodilatory pathways

Vascular smooth muscle and endothelial vasodilatory pathways represent the integrated signaling systems, such as the Nitric Oxide (NO)/cGMP and Prostacyclin (PGI2)/cAMP pathways, that regulate vascular tone and blood pressure (StatPearls, 2023, NBK554423). The endothelium releases vasodilators like NO, produced by endothelial nitric oxide synthase (eNOS), which activates soluble guanylate cyclase (sGC) in smooth muscle cells to increase cGMP, leading to relaxation (Nature Reviews Cardiology, 2016). Additionally, the endothelium-derived hyperpolarizing factor (EDHF) pathway involves potassium channel activation to induce hyperpolarization and vasodilation (American Journal of Physiology, 2011). Dysfunction in these pathways is a primary driver of cardiovascular diseases, including hypertension, atherosclerosis, and pulmonary arterial hypertension (Circulation Research, 2019). Therapeutic agents target these pathways by providing exogenous NO (nitrates), inhibiting cGMP degradation (PDE5 inhibitors like sildenafil), or directly stimulating sGC (riociguat) to restore vascular function (Journal of the American College of Cardiology, 2021). Overall, these pathways represent a multi-faceted therapeutic landscape for managing cardiovascular and pulmonary vascular health.

Other names

Endothelium-dependent relaxationVascular relaxation pathwaysNO-sGC-cGMP signaling pathwayProstacyclin signaling pathwayEndothelium-derived hyperpolarizing factor pathway

The mechanism involves the activation of soluble guanylate cyclase (sGC) by nitric oxide or the activation of adenylate cyclase by prostacyclin, leading to increased levels of cGMP or cAMP, respectively; these second messengers activate protein kinases (PKG/PKA) that reduce intracellular calcium levels and decrease the sensitivity of the contractile apparatus in vascular smooth muscle cells (StatPearls, 2023; Nature Reviews Cardiology, 2016).