Hemodynamic forces and vascular cell communication in arteries.

As the interface between the blood and the rest of the vessel wall, the endothelium is directly affected by hemodynamic shear stress (frictional) forces that locally regulate vascular tone and are implicated in the localization of atherosclerosis. There are many diverse responses of endothelial cells to hemodynamically related mechanical stresses ranging from ion channel activation to gene regulatory events. The processes of force transmission from the blood to the cell, and force transduction within the endothelium to electrophysiologic, biochemical, and transcriptional responses are poorly understood. This article reviews the principal mechanisms currently thought to be involved and outlines the signal pathways from the endothelium to underlying smooth-muscle cells.