Computational studies of ion-water flux coupling in the airway
epithelium: i. construction of model.
Novotny, Janet A., and Eric Jakobsson.
National Center for Supercomputing Applications, The Beckman
Institute and Department of Physiology and Biophysics, University of
Illinois, Urbana, IL 61801
APStracts 2:0417C, 1995.
A mathematical model of ion and water transport across the airway
epithelium is presented. The model consists of twelve state
variables, representing ion concentrations, volumes, and membrane
potentials. All osmotically significant membrane transport processes
for which there is conclusive experimental evidence are included:
passive apical sodium and chloride movement, basolateral sodium
-potassium pumping, basolateral sodium-potassium-chloride cotransport,
passive basolateral potassium movement, nonselective passive
paracellular ion motion, and water transport across all membranes.
Ion movements are described by Michaelis-Menton kinetics or by the
constant field flux equation. Model parameters were established with
Ussing chamber data. Model behavior was validated by comparing in
vitro simulations with experimental results. The model accurately
reproduced short-circuit chloride and sodium fluxes, short-circuit
current, and open-circuit membrane potentials from Ussing chamber
data in both the secreting and non-secreting states. The model was
then used to describe the behavior of the airway epithelium in vivo,
in which case the apical electrolyte compartment is small and of
variable size and ionic composition.
Received 12 September 1994; accepted in final form 16 November
1995.
APS Manuscript Number C542-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95