Heterogeneity of the intrahepatic biliary epithelium

Figure 3 Working model for the heterogeneity of the intrahepatic biliary epithelium. The model proposes that: (1) bile ducts are morphologically heterogeneous with small ducts lined by small cholangiocytes and large ducts lined by large cholangiocytes; (2) small and large ducts similarly express both γ-GT and cytokeratin-19; and (3) large (but not small) ducts express the secretin and somatostatin receptor, CFTR and Cl^-/HCO₃^- and respond physiologically to these two hormones. The model also shows that following BDL, only large cholangiocytes proliferate and that a single dose of CCl₄ induces damage and loss of large duct function, whereas small cholangiocytes (resistant to CCl₄) de novo proliferate and secrete to compensate for the loss of large duct function. Reproduced with permission from Ref. 73.