Estimation of the drug activities. Number of * denotes statistical significance at * p < 0.05, ** p < 0.01, or *** p < 0.001, respectively, n ≥ 5. (A) Effects of 500 µM of the compounds studied on the ASIC3 activated by pH drop from 7.4 to 6.85. Compounds were applied simultaneously with activation. (B,C) Representative examples of ASIC3 responses in control and in the presence of IEM-2044 (B) and IEM-2174 (C) when activated by pH drop from 7.4 to 6.85. (D) effects of 500 µM of the compounds studied on the ASIC3 activated by pH drop from 7.4 to 6.0. Compounds were applied simultaneously with activation. (E,F) Representative examples of ASIC3 responses in control and in the presence of IEM-2044 (E) and IEM-2174 (F) when activated by pH drop from 7.4 to 6.0.