Endothelial Modulation of Myocardial Contraction: a Novel Cardioregulatory Mechanism?

The vascular endothelium consists of a monolayer of cells forming a continuous lining of all blood vessels (with the exception of the spleen). As such, it is in intimate contact with every tissue and is thus in a prime position to exert influence over organ function. The heart contains two types of endothelial cells; vascular and endocardial. Although similar, they show both anatomical and functional differences [1]. The myocardium is richly vascularized, and it has been estimated that any cardiac myocyte is only a few microns away from a capillary vascular endothelial cell. Endocardial endothelial cells (EEC), by contrast, line the cardiac cavities and are in close contact with a relatively small mass of myocardium.