Taurocholate prevents the loss of intrahepatic bile ducts due to vagotomy in bile duct-ligated rats

Am J Physiol Gastrointest Liver Physiol. 2003 May;284(5):G837-52. doi: 10.1152/ajpgi.00398.2002. Epub 2003 Jan 29.

Abstract

The aim of this study was to determine whether taurocholate prevents vagotomy-induced cholangiocyte apoptosis. After bile duct ligation (BDL) + vagotomy, rats were fed taurocholate for 1 wk in the absence or presence of wortmannin. Caspase involvement was evaluated by measurement of caspase 8, 9, and 3 activities. Proliferation was determined by morphometry and PCNA immunoblots. Changes in phosphatidylinositol 3-kinase (PI3-kinase) activity were estimated by the expression of the phosphorylated Akt protein. Apically located Na(+)-dependent bile acid transporter (ABAT) expression and activity were evaluated by immunoblots and [(3)H]taurocholate uptake, respectively. Cholangiocyte apoptosis increased, whereas proliferation decreased in BDL + vagotomy rats. Taurocholate feeding prevented vagotomy effects on cholangiocyte functions, which were abolished by wortmannin. ABAT expression and activity as well as phosphorylated Akt protein expression were reduced by vagotomy but restored by taurocholate. The activities of caspase 8, 9, and 3 increased in BDL + vagotomy rats but were restored by taurocholate. The protective effect of taurocholate was associated with maintenance of ABAT activity, downregulation of caspase 8, 9, and 3, and activation of PI3-kinase. Bile acids are important in modulating cholangiocyte proliferation in denervated livers.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Apoptosis / drug effects
  • Bile Acids and Salts / metabolism
  • Bile Ducts, Intrahepatic / drug effects*
  • Bile Ducts, Intrahepatic / pathology*
  • Caspases / metabolism
  • Cell Division / drug effects
  • Ligation
  • Liver / innervation
  • Liver / physiology
  • Male
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation / drug effects
  • Protein Serine-Threonine Kinases*
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-akt
  • Rats
  • Rats, Inbred F344
  • Taurocholic Acid / pharmacology*
  • Vagotomy*
  • Vagus Nerve / surgery
  • Wortmannin

Substances

  • Androstadienes
  • Bile Acids and Salts
  • Proto-Oncogene Proteins
  • Taurocholic Acid
  • Akt1 protein, rat
  • Protein Serine-Threonine Kinases
  • Proto-Oncogene Proteins c-akt
  • Caspases
  • Wortmannin