Table 2.
Effects of mexiletine on Nav1.4 WT and M1476I currents
| Recovery from mexiletine block | ||||||||
|---|---|---|---|---|---|---|---|---|
| Activation | Steady-state inactivation | 40 ms conditioning pulse | 500 ms conditioning pulse | |||||
| V1/2 (mV) (n) | kv (mV) (n) | V1/2 (mV) (n) | kv (mV) (n) | τ1 (ms) Fraction τ1 (%) (n) | τ2 (ms) Fraction τ2 (%) (n) | τ1 (ms) Fraction τ1 (%) (n) | τ2 (ms) Fraction τ2 (%) (n) | |
| M1476I | −48.7 ± 1.4 (10) | −4.8 ± 0.2 (10) | −83.1 ± 1.3† (15) | 4.5 ± 0.1* (15) | 0.75 ± 0.01† | 530.8 ± 54.4* | 6.93 ± 0.7† | 867.38 ± 45.1 |
| 35.9 ± 2.3 | 71.0 ± 1.5 | 18.4 ± 0.7 | 82.4 ± 0.9 | |||||
| (12) | (12) | (10) | (10) | |||||
| WT | −48.0 ± 1.3 (9) | −4.6 ± 0.2 (9) | −88.6 ± 0.8 (14) | 4.2 ± 0.1 (14) | 3.5 ± 0.4 | 700.8 ± 51.2 | 11.4 ± 1.0 | 963.8 ± 37.7 |
| 41.1 ± 3.7 | 61.2 ± 3.5 | 15.1 ± 1.0 | 84.9 ± 1.2 | |||||
| (10) | (10) | (10) | (10) | |||||
*
P < 0.5,
†
P < 0.01, data were significantly different for mutant channels when compared to WT.