Sodium ions occurring in food are thought to be detected, at least in part,
through specific amiloride-sensitive, sodium channels (ASSCs) localized in
taste receptor cells. Cells within taste buds are morphologically heteroge
neous, and include taste receptor cells and other cells that could perform
a support or even transduction role. It is not known whether subsets of the
taste bud cells express ASSCs, and whether the properties of these channel
s are similar. By applying the patch-clamp technique to morphologically dis
tinct cells, the supporting wing cells, isolated from the frog taste disk,
I have found functional ASSCs that are moderately sensitive to amiloride (K
i 3-4 muM) and which are distinctly lower in affinity for amiloride than re
ported frog taste receptor cells (K-i 0.2 muM). These results support the h
ypotheses of the existence of distinct, functional ASSCs in different cell
morphotypes, at least in frog taste organs. Neuro Report 12:1315-1321 (C) 2
001 Lippincott Williams & Wilkins.