Heterogeneity of endothelial function within the circulation.

As our understanding of endothelial function continues to evolve, it has become increasingly clear that the peripheral vasculature exhibits striking regional and segmental heterogeneity in the influence of the endothelial cell layer on vascular tone. This heterogeneity encompasses not only the normal interactions between endothelium-derived factors and vascular smooth muscle, but also the way in which these interactions can change during juvenile growth or in disease states such as hypertension. The underlying causes of this heterogeneity are multifactorial and include intrinsic differences among endothelial cell populations and differences in the endothelial cell microenvironment.