Functional Heterogeneity of the Intrahepatic Biliary Epithelium
In this book chapter, we discuss the latest findings related to the concept that the bile duct system is heterogeneous regarding: (i) morphological characteristics; (ii) physiological response to gastrointestinal hormones/peptides; (iii) apoptotic and proliferative activity in response to liver injury/toxins. We will first review the anatomy and morphological features of the bile duct system. Following a brief overview on cholangiocyte functions, we will describe the in vivo models and in vitro experimental tools allowing us to define that small and large cholangiocytes (which line small and large bile ducts) are functionally heterogeneous. Following an overview on the receptors/transporters/channels that are differentially expressed by cholangiocytes, we will discuss the different sized ducts that differentially respond to hepatic injury/toxins.