Human salt taste and the lingual surface potential correlate.
We have demonstrated in humans that Na(+) evokes changes in the lingual surface potential (LSP) using a custom chamber. To assess whether a relationship exists between the Na(+)-evoked changes in the LSP and the intensity of salt taste, we measured the LSP and the intensity of salt taste simultaneously in 7 subjects using test solutions (50, 100, 300, and 1000 mM NaCl) presented in random order. The evoked LSPs and intensity scores correlated with one another well (r(2) = 0.992, P < 0.01). We then screened 14 subjects for their ability to discriminate between 100 and 300 mM NaCl using the chamber. Three subjects were consistently capable of distinguishing the salt concentrations. In these 3 subjects, an inhibitor of the epithelial sodium channel, amiloride (10 muM), blocked the ability to distinguish salt concentrations and affected the LSP. These data suggest that the LSP may be a component of the signal transduction system involved in human salt taste. In adept salt tasters, an amiloride-sensitive mechanism appears to have a role in distinguishing salt concentrations.
Feldman
George M
GM
Medical Service, Hunter Holmes McGuire Veterans Affairs Medical Center, Richmond, VA 23249, USA. george.feldman@va.gov
Heck
Gerard L
GL
Smith
Nancy L
NL
D000328:Adult; D000584:Amiloride / Q000494:pharmacology; D004566:Electrodes; D005260:Female; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008875:Middle Aged; D015398:Signal Transduction; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000378:metabolism; D012965:Sodium Chloride / Q000737:chemistry / Q000494:pharmacology*; D013649:Taste / Q000502:physiology*; D014059:Tongue / Q000502:physiology*
D026941:Sodium Channel Blockers; D015222:Sodium Channels; D012965:Sodium Chloride; D000584:Amiloride