Cell-cell communication in the vessel wall

Abstract

Intercellular communication between cells within the blood vessel wall plays an important role in the control of artery diameter. The endothelial cells lining the lumen of arteries can evoke smooth muscle hyperpolarization both by the release of a factor (EDHF) and by direct cell-cell coupling through gap junctions. Hyperpolarizing current can spread rapidly to cause widespread vasodilatation, and thus increase blood flow to that segment. In addition to the spread of current, small molecules, such as Ca 2 + , can also pass between cells, but at a much reduced rate. Instead of co-ordinating changes in diameter, intercellular Ca 2 + signalling acts to amplify and, in special cases, modulate vascular responses. Together, direct cell-cell communication enables the blood vessel wall to act as a functional syncytium, which is influenced by surrounding tissues and nerves, and blood constituents.