AJP - Gastrointestinal and Liver Physiology, Vol 257, Issue 3 475-G487, Copyright © 1989 by American Physiological Society
Network thermodynamic model of rat lingual epithelium: effects of hyperosmotic NaCl
M. L. Fidelman and S. Mierson
Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.
A network thermodynamic model was developed to describe steady-state and
transient ion flows (Na+, K+, and Cl-) and related electrical events in the
rat lingual epithelium. The model, which uses only standard assumptions
about topology and membrane ion transport processes from other tight
epithelia, successfully simulates steady-state transepithelial electrical
measurements seen in the in vitro rat dorsal lingual epithelium for a wide
range (50-2,000 mM) of mucosal NaCl concentrations. It also simulates the
intracellular depolarization and subsequent repolarization observed in situ
in rat taste cells in response to a mucosal hyperosmotic NaCl stimulus.
Because the intracellular potential has been identified with the receptor
potential for gustation, the depolarization and repolarization may explain
both the phasic and tonic components of taste nerve excitation in response
to a salt stimulus. This study suggests that a better understanding of
taste transduction may be gained by focusing more attention on the
transport properties and mechanisms of lingual epithelia.
