Calcium Signaling in Cholangiocytes

Evidence suggests that Ca²⁺ is able to regulate such a wide range of cellular activities by the manners in which Ca²⁺ signals are encoded. For example, cells can encode signals using both amplitude modulation and frequency modulation of Ca²⁺ transients, and can even independently modulate Ca²⁺ signals in different regions of an individual cell. These general principles of Ca²⁺ signaling have been determined based on work involving a number of cell systems. Cholangiocytes are polarized epithelial cells, and receptors that link to Ca²⁺ signaling have been identified in both the apical and basolateral domain of the plasma membrane. The patterns by which Ca²⁺ increases over space and time are important components of Ca²⁺ signaling. For example, Ca²⁺ -mediated secretion depends upon spatial patterns such as Ca²⁺ gradients and waves in cell types as diverse as neurons, adrenal chromaffin cells, and exocrine pancreas.