Amiloride alters lick rate responses to NaCl and KCl in rats

The role of cation channels on taste cell membranes to salt taste sensation was assessed in rats. We measured the number of licks during multiple 10-s presentations of NaCl and KCl concentrations (0.05, 0.09, 0.16, 0.28, 0.5 M) dissolved in either water or in 100 microM amiloride, a sodium-channel blocker. The number of licks to water and 0.3 M sucrose was also measured. The number of licks to NaCl was significantly lower and the number of licks to KCl was significantly higher when these test solutions were dissolved in amiloride than in water. There were no differences in lick responses to water and sucrose. These results suggest that amiloride may have altered the taste of NaCl and KCl. The results are discussed in relationship to prior electrophysiological studies characterizing the effect of amiloride in blocking salt responses of the chorda tympani nerve.