Cholangiocytes are epithelial cells that line the intra-and extrahepatic ducts of the biliary
tree. The main physiologic function of cholangiocytes is modification of hepatocyte-derived
bile, an intricate process regulated by hormones, peptides, nucleotides, neurotransmitters,
and other molecules through intracellular signaling pathways and cascades. The
mechanisms and regulation of bile modification are reviewed herein.