NaCl and water responses across the frog tongue epithelium in vitro

Isolated dorsal epithelium of the frog tongue elicited transepithelial NaCl and water responses across the tissue when NaCl was added to or removed from the adapting Ringer solution in the mucosal surface, respectively. The NaCl response which was a negative polarization in the mucosa with respect to the serosa was associated with a decrease in resistance across the tissue, whereas the water response which was a positive polarization was associated with an increase in the resistance. The decrease and increase in the tissue resistance remained unchanged by various polarizations of the transepithelial potential difference across the tissue. Characteristics of the NaCl and water responses were similar in many respects to those in the taste cells and nerves of frogs. Thus the NaCl and water responses may relate to taste reception.