Diversity in unity: The biochemical composition of the endothelial cell surface varies between the vascular beds

The vascular endothelium represents a population of squamous epithelial cells characterized by a particular histological localization (intima of blood vessels) and by several physiological functions such as the transport of substances between blood and tissues, the modulation of the vascular tone, the control of blood coagulation and that of the leukocyte extravasation. In spite of all these elements in common and of an identical embryonic origin, endothelial cells show definite morphological and physiological variations that divide them into types and subtypes, each specifically associated to various categories of organs. Even within the vasculature of the same organ, there are clear segmental (arterial/capillary/venous) differentiations of the endothelial cells. While the morphological and physiological differences between endothelial cells are well documented, there are very few data on the biochemistry underlying this heterogeneity. This work presents several data suggesting that, at present, the domain is ripe for a comprehensive analysis of this biochemical diversity, at least in what concerns the luminal aspect of the endothelial plasmalemma, a compartment of crucial importance in the biology and pathology of the cardiovascular system.