ABSTRACT
Considering the aggregated mass of the endothelium that equals that of the liver (about 1000 g), the critical role in mediating various and numerous functions, such as plasma tissue exchanges, vessel wall tone, blood fluidity, and selective transport via specific receptors for plasma molecules, the vascular endothelium as a whole can be regarded as a multifunctional organ with a broad spectrum of properties and activities. There is substantial evidence that the highly heterogeneous endothelium is morphologically and functionally integrated in the host organ in which it resides at the level of which, besides the common roles, may play specific functions such as integrator and transducer of bloodborne signals, regulator of vascular growth or metabolism of hormones and vasoactive mediators.
