Expression and localization of amiloride-sensitive sodium channel indicate a role for non-taste cells in taste perception

Salty taste is blocked by the diuretic amiloride, which inhibits specific sodium channels. We have isolated an amiloride-sensitive sodium channel (ASSC) from taste tissues by polymerase chain reaction and screening of a cDNA library prepared from rat circumvallate papillae. Northern analysis reveals ASSC in taste and non-taste tissues with the highest level of expression of ASSC in the lung. In situ hybridization establishes ASSC localizations in the epithelia of lung and colon as well as tongue epithelial layers containing and lacking taste buds. These results support a model in which ASSC in non-taste cells regulates responses of taste cells to salt as well as other tastants.