Endothelium, endocardium, and cardiac contraction.

Abstract

t is now recognised that vascular endothelium plays Im any functional roles including that of modulating vascular smooth muscle tone through the release of vasoactive agents such as endothelium derived relaxing factor (EDRF).’-’ The heart phylogenetically is a specialised development of the vascular system. Its intracavitary lining of endocardial endothelium might therefore be expected to have properties in common with those of endothelium lining the rest of the vascular tree. Agents produced by endothelium might also influence contraction of underlying cardiac muscle as they do in vascular smooth muscle. This has indeed now been shown to be the case