Computational studies of ion-water flux coupling in the airway
epithelium: ii. role of specific transport mechanisms.
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 2:0418C, 1995.
Ion and water balance by the in vivo airway epithelium was
investigated utilizing dynamic computer modeling. Parameters of the
osmotically significant transport processes were varied to assess the
sensitivity of water transport and fluid composition to transport
perturbations. Establishment and regulation of water secretion is a
coordinated function of at least seven different ion transport
processes: basolateral passive potassium transport, basolateral
active sodium-potassium transport, basolateral sodium-potassium
-chloride cotransport, apical passive sodium and chloride transport,
and diffusion of sodium and chloride across the paracellular path. We
found that apical chloride permeability at a level reported for
cystic fibrosis is sufficient to cause the airway dehydration
characteristic of cystic fibrosis. Given the reduction in apical PCl
seen in cystic fibrosis, a reduction in apical sodium permeability
can potentially compensate completely for the airway dehydration
associated with the cystic fibrosis genetic defect. Other simulations
presented here address the importance of various membrane transport
processes in airway epithelium water balance and the sensitivity of
epithelium water balance to ion transport perturbations.
Received 12 September 1994; accepted in final form 16 November
1995.
APS Manuscript Number C543-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95