Calcium Signaling in the Liver

Intracellular free Ca 2+ ([Ca 2+ ]i) is a highly versatile second messenger that regulates a wide range of functions in every type of cell and tissue. To achieve this versatility, the Ca 2+ signaling system operates in a variety of ways to regulate cellular processes that function over a wide dynamic range. This is particularly well exemplified for Ca 2+ signals in the liver, which modulate diverse and specialized functions such as bile secretion, glucose metabolism, cell proliferation, and apoptosis. These Ca 2+ signals are organized to control distinct cellular processes through tight spatial and temporal coordination of [Ca 2+ ]i signals, both within and between cells. This article will review the machinery responsible for the formation of Ca 2+ signals in the liver, the types of subcellular, cellular, and intercellular signals that occur, the physiological role of Ca 2+ signaling in the liver, and the role of Ca 2+ signaling in liver disease.