ABSTRACT
The objective of this article is to summarize the findings related to the notion that
cholangiocytes, within small and large intrahepatic ducts, are heterogeneous regarding
(1) morphology; (2) secretion in response to hormones and peptides and to bile acids;
and (3) proliferation in response to injury or toxins, including bile duct ligation
(BDL), acute carbon tetrachloride (CCl4) administration, chronic feeding of bile salts (i.e., taurocholate [TC] or taurolithocholate
[TLC]) or α-naphthylisothiocyanate (ANIT). After an overview of the morphology of
the biliary epithelium, we provide a summary of cholangiocyte function, the in vivo
models, and the in vitro experimental tools (i.e., small and large cholangiocytes
or small and large intrahepatic bile duct units [IBDU]), which allowed us to demonstrate
cholangiocyte heterogeneity. After a discussion on the receptors, transporters, and
channels that are heterogeneously expressed by cholangiocytes, we discuss the different-sized
ducts that differentially respond to injury and toxins. Finally, we review the human
diseases that selectively target specific-sized ducts.
KEYWORDS
Ductal secretion - intrahepatic biliary epithelium - liver injury - proliferation
- secretin