title: Computation of pump-leak flux balance in animal cells.
abstract: OBJECTIVE
  Many vital processes in animal cells depend on monovalent ion transport across the plasma membrane via specific pathways. Their operation is described by a set of nonlinear and transcendental equations that cannot be solved analytically. Previous computations had been optimized for certain cell types and included parameters whose experimental determination can be challenging.
  
  
  METHODS
  We have developed a simpler and a more universal computational approach by using fewer kinetic parameters derived from the data related to cell balanced state. A file is provided for calculating unidirectional Na(+), K(+), and Cl(-) fluxes via all major pathways (i.e. the Na/K pump, Na(+), K(+), Cl(-) channels, and NKCC, KC and NC cotransporters) under a balanced state and during transient processes.
  
  
  RESULTS
  The data on the Na(+), K(+), and Cl(-) distribution and the pump flux of K(+) (Rb(+)) are obtained on U937 cells before and after inhibiting the pump with ouabain. There was a good match between the results of calculations and the experimentally measured dynamics of ion redistribution caused by blocking the pump.
  
  
  CONCLUSIONS
  The presented approach can serve as an effective tool for analyzing monovalent ion transport in the whole cell, determination of the rate coefficients for ion transfer via major pathways and studying their alteration under various conditions.
authors.affiliation: St-Petersburg State Polytechnical University, St-Petersburg, Russia.
authors.forename: Igor A
authors.initials: IA
authors.lastname: Vereninov
authors.forename: Valentina E
authors.initials: VE
authors.lastname: Yurinskaya
authors.forename: Michael A
authors.initials: MA
authors.lastname: Model
authors.forename: Florian
authors.initials: F
authors.lastname: Lang
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Vereninov
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism; D006801:Humans; D017136:Ion Transport / Q000502:physiology*; D007477:Ions / Q000378:metabolism; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism*; D020298:U937 Cells; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D002712:Chlorides; D007477:Ions; D028021:Sodium-Potassium-Chloride Symporters; D010042:Ouabain; D012964:Sodium; D011188:Potassium