Table 1.
INa3 in P and VM cells and its changes with lower Vh
| Vh (mV) | Param | VM cells | P cells |
|---|---|---|---|
| −80 | Th (mV) | −46.7 ± 1.1 | −53.3 ± 1.9* |
| INa3 (pA) | −168 ± 52 (18/18) | −217 ± 102 (13/18) | |
| τf (msec) | 15.3 ± 2.9 | 10.5 ± 2.8 | |
| τs (msec) | 82.7 ± 11.9 | 55.9 ± 12.9 | |
| −70 | Th (mV) | −43.3 ± 1.3 | −52.5 ± 1.8* |
| INa3 (pA) | −189 ± 66 (15/16) | −190 ± 63 (11/16) | |
| −60 | Th (mV) | −38.5 ± 1.0 | −46.6 ± 1.2* |
| INa3 (pA) | −120 ± 29 (12/15) | −235 ± 71 (14/15 | |
| −50 | Th (mV) | −33.6 ± 1.5 | −35.6 ± 2.0 |
| INa3 (pA) | −179 ± 76 (11/16) | −155 ± 42 (14/16) | |
| −40 | Th (mV) | −21.0 ± 1.0 | −27.1 ± 1.8* |
| INa3 (pA) | −29.9 ± 18.3 (3/10) | −84 ± 35 (6/9) |
Vh (mV), holding potential in mV; Param, parameters measured; VM cells, data from ventricular myocardial cells; P cells, data from Purkinje cells; Th (mV), threshold potential in mV of INa3; INa3 (pA), amplitude in pA of INa3 measured as the difference between its peak and the end of the step; τf (msec) and τs (msec), fast and slow time constants, respectively, of INa3 inactivation; Numbers in parenthesis (e.g., 18/18), number of cells in which INa3 was present over the total number of cells studied; *statistically significant difference between P and VM cells data.