Bicarbonate umbrella and its distribution of the bile duct

Shinji Shimoda

Research output: Chapter in Book/Report/Conference proceedingChapter


Bicarbonate umbrella is a cell protective function from cytotoxic molecules by extracellular secretion of bicarbonate. Small bile ducts use this function to protect from hydrophobic bile acids, damage-associated molecular patterns (DAMPs), and pathogen-associated molecular patterns (PAMPs). On the other hand, primary biliary cholangitis (PBC) whose head of issue is characterized by the destruction of small bile ducts with the dysfunction of the bicarbonate umbrella as Cl-/HCO3- exchanger anion exchanger 2 (AE2) activation. PBC has two features; an organ-specific autoimmune disease and a cytopathic biliary disease due to bile exposure that has strong cytotoxicity. Thus, bile ducts of PBC are exposed to two types of bile acids; hydrophilic and cytoprotective ursodeoxycholic acid (UDCA) and hyrophobic and cytotoxic bile acids. UDCA is effective to protect bile exposure in the early phase of the disease, and UDCA is not so effective in the advanced phase where abnormal acquired immunity has central roles for destruction of the small bile ducts.

Original languageEnglish
Title of host publicationPathology of the Bile Duct
PublisherSpringer Singapore
Number of pages6
ISBN (Electronic)9789811035005
ISBN (Print)9789811034992
Publication statusPublished - May 26 2017

All Science Journal Classification (ASJC) codes

  • Medicine(all)


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