The adult pancreatic ductal epithelial tree serves two critical physiologic functions: first, to secrete bicarbonate-rich fluid to dilute and control the pH of the protein concentrate secreted by acinar cells and second, to convey this mixture to the intestine.
The ductal tree is structured so that it extends distally into clusters of acinar cells. Terminal end duct cells that interface with acini are called centroacinar cells. More proximal intercalated ducts merge to form larger intralobular ducts (lined by cuboidal epithelial cells), which merge to form interlobular ducts, which finally merge to form the main duct (lined by simple columnar epithelial cells) that traverses the pancreas to the duodenum, delivering fluid laden with digestive enzymes.
Epithelial morphogenesis is controlled by Rho family GTPases, which regulate cell polarity, adhesion, and migration by organizing the actin cytoskeleton. In the pancreas, Cdc42, a Rho family member, is critical for cell polarization during early morphogenesis, inducing tubulogenesis and microlumen formation. Strad13, another Rho family member, is also important for tubulogenesis induction.
EMBRYONIC DEVELOPMENT & STEM CELL COMPENDIUM
