Figure 2: Urine-activated Cl⁻ current requires Ca²⁺.

Sample traces (a) and average amplitude (b) of whole-cell currents in response to urine activation recorded under the three different extracellular Ca²⁺ concentrations ([Ca²⁺]_ext). Sample traces (c) and average amplitude (d) of whole-cell currents recorded using 1mM EGTA (n=12) or 5 mM BAPTA (n=6) in pipette solution at different extracellular Cl⁻ concentrations ([Cl]_ext). The same cells were recorded before and after external Cl⁻ substitution with gluconate. The difference in current amplitude indicated in c is attributed to Cl⁻ channels. Black lines above the traces indicate the duration of urine application. Error bars indicate standard errors. **P<0.01; NS, not significant.