Table 1.
Fitting values of amiloride and NS383 at rat and human acid‐sensing ion channels (ASICs). Amiloride and NS383 inhibition concentration response relationships were obtained as described in the Figure 2 legend. Data points were fitted to the Hill equation using nonlinear regression where the top value (representing infinite compound dilution) was set to 1 and the bottom value to 0 for ASIC1a, ASIC2a, ASIC3, and rASIC1a+3.Variable bottom was used for NS383 at ASIC1a+2a, ASIC2a+3, and hASIC1a+3 as saturating compound concentrations clearly did not cause complete inhibition. Data are presented as EC50 in μM ± SE, inhibition level in % (where bottom = 0 reflect 100% inhibition) and Hill slopes ± SE
| Amiloride (rat receptors) | NS383 (rat receptors) | NS383 (human receptors) | ||||
|---|---|---|---|---|---|---|
| EC50 (inhibition) | Hill slope | EC50 (inhibition) | Hill slope | EC50 (inhibition) | Hill slope | |
| μM (%) | μM (%) | μM (%) | ||||
| ASIC1a | 12 ± 2 (100) | −0.71 ± 0.07 | 0.44 ± 0.06 (100) | −0.75 ± 0.09 | 0.12 ± 0.02 (100) | −1.0 ± 0.1 |
| ASIC2a | 20 ± 3 (100) | −1.1 ± 0.2 | no effect | no effect | ||
| ASIC3 | 35 ± 8 (100) | −0.79 ± 0.15 | 2.1 ± 0.2 (100) | −1.2 ± 0.1 | no effect | |
| ASIC1a+2a | not determined | 0.87 ± 0.44 (44) | −1.3 ± 0.6 | 0.33 ± 0.06 (59) | −1.3 ± 0.3 | |
| ASIC1a+3 | not determined | 0.79 ± 0.11 (100) | −0.96 ± 0.12 | 0.69 ± 0.24 (81) | −1.2 ± 0.4 | |
| ASIC2a+3 | not determined | 4.5 ± 4.3 (51) | −1.0 ± 0.5 | no effect | ||