Abstract
Calcium (Ca(2+)) is a versatile second messenger that regulates a number of cellular processes in virtually every type of cell. The inositol 1,4,5-trisphosphate receptor (ITPR) is the only intracellular Ca(2+) release channel in cholangiocytes, and is therefore responsible for Ca(2+)-mediated processes in these cells. This review will discuss the machinery responsible for Ca(2+) signals in these cells, as well as experimental models used to investigate cholangiocyte Ca(2+) signaling. We will also discuss the role of Ca(2+) in the normal and abnormal regulation of secretion and apoptosis in cholangiocytes, two of the best characterized processes mediated by Ca(2+) in this cell type.