Intercellular Ca<sup>2+</sup> signalling: The artery wall
The fact that many cells in the cardiovascular system are coupled via gap junctions enables direct intercellular Ca 2+ signalling. Ca 2+ ions and/or inositol trisphosphate (IP 3 ) can pass through these aqueous pores. Cell-cell coupling can occur between cells of the same type, or via special junctions between adjacent cells of different types. Homocellular coupling acts to amplify and prolong Ca 2+ signals, whereas heterocellular coupling allows complex interactions between the cells, including the modulation of their respective responses. This review will focus on the interactions between cells that form the blood vessel wall, illustrating how cell-cell communication defines important physiological functions. © 2001 Academic Press.