Table 2.
Biophysical properties of sodium currents conducted by wild-type, R104W, and R121W Nav1.5 channels. Peak sodium current (INa) densities are extracted from the respective IV curves. WT, wild type; emtpy v., empty vector. Data are presented as mean ± SEM and are compared to wild-type values. *, p < 0.05; **, p < 0.01; **, p < 0.005; ***, p < 0.001; ****, p < 0.0005. ND, non-detectable. Numbers of cells are indicated in parentheses.
|
INa density |
Steady-state inactivation |
Activation |
|||
|---|---|---|---|---|---|
| pA/pF | k | V1/2 (mV) | k | V1/2 (mV) | |
| Nav1.5 WT | −86.6 ± 11.4 (n = 9) | 5.3 ± 0.2 (n = 11) | −73.2 ± 0.5 (n = 11) | 6.6 ± 0.2 (n = 9) | −22.7 ± 0.6 (n = 9) |
| R104W | ND (n = 7) | n/a | n/a | n/a | n/a |
| R121W | ND (n = 7) | n/a | n/a | n/a | n/a |
| WT + empty v. | −38.4 ± 3.4 (n = 5)**** | 4.8 ± 0.1 (n = 5) | −74.4 ± 0.9 (n = 5) | 6.9 ± 0.3 (n = 5) | −20.0 ± 0.2 (n = 5)* |
| WT + R104W | −23.1 ± 4.6 (n = 9)**** | 5.4 ± 0.2 (n = 11) | −75.9 ± 0.5 (n = 11)* | 7.5 ± 0.3 (n = 7)* | −19.5 ± 0.7 (n = 7)** |
| WT + R121W | −46.9 ± 3.4 (n = 12)**** | 5.2 ± 0.2 (n = 6) | −72.5 ± 1.3 (n = 6) | 7.4 ± 0.3 (n = 10) | −20.3 ± 0.5 (n = 10)** |