Apical Cl-/HCO3- exchanger stoichiometry in the modeling of HCO3- transport by pancreatic duct epithelium

• Yamaguchi Makoto

  Department of Human Nutrition, Nagoya University Graduate School of Medicine

• Ishiguro Hiroshi

  Department of Human Nutrition, Nagoya University Graduate School of Medicine

• Steward Martin

  Faculty of Life Sciences, University of Manchester

• Sohma Yoshiro

  Department of Pharmacology, School of Medicine, Keio University

• Yamamoto Akiko

  Department of Human Nutrition, Nagoya University Graduate School of Medicine

• Shimouchi Akito

  Department of Etiology and Pathogenesis, National Cardiovascular Center Research Institute

• Kondo Takaharu

  Department of Human Nutrition, Nagoya University Graduate School of Medicine

Abstract

Pancreatic duct cells secrete a HCO₃^--rich (∼140 mM) fluid. Using a computer model of the pancreatic duct, Sohma, et al. have demonstrated that the activity of a Cl^-/HCO₃^- exchanger with a 1: 1 stoichiometry at the apical membrane would have to be suppressed in order to achieve such a HCO₃^--rich secretion. Recently the apical exchanger in pancreatic ducts has been identified as SLC26A6 and this probably mediates most of Cl^--dependent HCO₃^- secretion across the apical membrane. SLC26A6 is reported to mediate electrogenic Cl^-/2HCO₃^- exchange when expressed in Xenopus oocytes. To assess the implications of this 1: 2 stoichiometry for HCO₃^- secretion, we have reconstructed the Sohma model using MATLAB/Simulink. To do this we have formulated an expression for the turnover rate of Cl^-/2HCO₃^- exchange using network thermodynamics and we have estimated the constants from published experimental data. Preliminary data suggest that the 1: 2 stoichiometry of SLC26A6 would favor HCO₃^- secretion at higher concentrations. J. Med. Invest. 56 Suppl.: 325-328, December, 2009

Journal

• The Journal of Medical Investigation

  The Journal of Medical Investigation 56 (Supplement), 325-328, 2009

  The University of Tokushima Faculty of Medicine

Keywords

• pancreatic duct cell
• mathematical model
• SLC26A6
• Cl<SUP>-</SUP>-HCO<SUB>3</SUB><SUP>-</SUP> exchanger

Details

• CRID: 1390001204243026688
• NII Article ID: 130004822630
• NII Book ID: AA11166929
• DOI: 10.2152/jmi.56.325
• ISSN: 13496867
• ISSN: 13431420
• Web Site: http://repo.lib.tokushima-u.ac.jp/111371
• Web Site: http://www.jstage.jst.go.jp/article/jmi/56/Supplement/56_Supplement_325/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2010325510
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed