Endothelium-dependent vascular responses: mediators and mechanisms

The nonthrombogenic and high solute and water permeability properties of the vascular endothelium have long been recognized as essential components of normal microvascular integrity. In addition to the more recent recognition of other hemostatic as well as proproliferative and cytoadhesive properties, the past decade has witnessed a growing awareness that this endothelial monolayer is also capable of intrinsic modulation of vascular tone by elaborating several potent vasoactive substances. Two impressive vasorelaxants are prostacyclin and endothelium-derived relaxation factor, the latter at least in part composed of nitric oxide.