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

Makoto Yamaguchi; Hiroshi Ishiguro; Martin Steward; Yoshiro Sohma; Akiko Yamamoto; Akito Shimouchi; Takaharu Kondo

doi:10.2152/jmi.56.325

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

Makoto Yamaguchi, Hiroshi Ishiguro, Martin Steward, Yoshiro Sohma, Akiko Yamamoto, Akito Shimouchi, Takaharu Kondo

Research output: Contribution to journal › Article › peer-review

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 HCO 3- 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-/2HCO 3- 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.

Original language	English
Pages (from-to)	325-328
Number of pages	3
Journal	Journal of Medical Investigation
Volume	56
Issue number	1
DOIs	https://doi.org/10.2152/jmi.56.325
Publication status	Published - 2009

Keywords

Cl--HCO 3- exchanger
Mathematical model
Pancreatic duct cell
SLC26A6

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http://medical.med.tokushima-u.ac.jp/jmi/vol56/pdf/v56_Supplement_p325.pdf

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

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 HCO 3- 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-/2HCO 3- 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.",

keywords = "Cl--HCO 3- exchanger, Mathematical model, Pancreatic duct cell, SLC26A6",

author = "Makoto Yamaguchi and Hiroshi Ishiguro and Martin Steward and Yoshiro Sohma and Akiko Yamamoto and Akito Shimouchi and Takaharu Kondo",

year = "2009",

doi = "10.2152/jmi.56.325",

language = "English",

volume = "56",

pages = "325--328",

journal = "Journal of Medical Investigation",

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T1 - Apical Cl-/HCO3- exchanger stoichiometry in the modeling of HCO3- transport by pancreatic duct epithelium

AU - Yamaguchi, Makoto

AU - Ishiguro, Hiroshi

AU - Steward, Martin

AU - Sohma, Yoshiro

AU - Yamamoto, Akiko

AU - Shimouchi, Akito

AU - Kondo, Takaharu

PY - 2009

Y1 - 2009

N2 - 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 HCO 3- 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-/2HCO 3- 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.

AB - 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 HCO 3- 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-/2HCO 3- 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.

KW - Cl--HCO 3- exchanger

KW - Mathematical model

KW - Pancreatic duct cell

KW - SLC26A6

U2 - 10.2152/jmi.56.325

DO - 10.2152/jmi.56.325

M3 - Article

SN - 1343-1420

VL - 56

SP - 325

EP - 328

JO - Journal of Medical Investigation

JF - Journal of Medical Investigation

IS - 1

ER -

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

Abstract

Keywords

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