Reversible and concentration-dependent inhibition of ASIC3 currents by tetracaine. A, B. Representative current traces and summary data showing reversible inhibition of the ASIC3 current expressed in Chinese Hamster Ovary cells (CHO) cells. ASIC3 current was induced by decreasing the extracellular pH from 7.4 to 4.5. Tetracaine was added to the pH 4.5 solution at a final concentration of 3 mM (Paired t test, n = 4; **p < 0.01). C, D. Representative current traces and summary data showing a concentration-dependent inhibition of the peak amplitude of ASIC3 currents by tetracaine. The IC50 value was 9.96 ± 1.88 mM (n = 5). Data were expressed as mean ± SD.