Calcium signalling in endothelial cells.

Vascular endothelial cells are ubiquitous for their presence in each and every vessel and unique for their multifunctional nature. A large number of endothelial functions depend to various extents on changes in intracellular Ca(2+) concentration. Reviewed are endothelial Ca(2+) stores, Ca(2+) channels, and in-out-in Ca(2+) signalling events, from ligand-binding on the plasma membrane into depletion of intracellular Ca(2+) stores and therefrom out to transplasmalemmal Ca(2+) entry that is of prime importance for many endothelial functions. Special emphasis is placed on mechanisms regulating store-operated Ca(2+) entry including a Ca(2+) influx factor, the vesicle secretion-like model, the conformational coupling model, the membrane potential, cytochrome P450, protein tyrosine kinase, myosin light chain kinase and nitric oxide.