Fatty acid modulation of k+ channels in taste receptor cells:
gustatory cues for dietary fat.
Gilbertson, Timothy A., D. Troy Fontenot, Lidong Liu, Huai Zhang &
W. Todd Monroe.
Pennington Biomedical Research Center, Louisiana State University,
Baton Rouge LA 70808-4124, USA
APStracts 3:0345C, 1996.
In an attempt to determine the chemosensory cues, if any, provided by
fats in the oral cavity, we have performed patch clamp recordings on
isolated rat taste receptor cells during application of free fatty
acids. Cis-polyunsaturated fatty acids when applied extracellularly
inhibit delayed rectifier K+ channels. In a subset of cells, these
fatty acids also enhance inwardly rectifying K+ currents. Saturated,
monounsaturated and trans polyunsaturated fatty acids have no
significant effect on K+ currents. These effects do not involve
activation of G protein-mediated pathways including protein kinase C
and protein kinase A, lipoxygenase pathways, cyclooxygenase pathways
nor cytochrome P450 pathways, consistent with direct effects on these
ion channels or closely associated proteins. The net effect of fatty
acids is to prolong stimulus-induced depolarizations of taste
receptor cells and we propose the effects on K+ channels represent
the mechanism by which fats are detected by receptor cells in the
oral cavity.
Received 17 September 1996; accepted in final form 23 October
1996.
APS Manuscript Number C539-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 November 1996