Table 1.
Voltage dependence of SSA and SSI for INa in ventricular cardiomyocytes from normal dogs and dogs with chronic heart failure
| SSI Parameters |
SSA Parameters |
|||||
|---|---|---|---|---|---|---|
| Conditions | V1/2A, mV | kA, mV | n | V1/2G, mV | kG, mV | n |
| Normal heart, INaT | ||||||
| Control siRNA | −82.0 ± 0.6 | −5.9 ± 0.8 | 7 | −41.3 ± 0.1 | 5.2 ± 0.4 | 5 |
| Navβ1-siRNA | −81.9 ± 0.7 | −6.2 ± 0.6 | 5 | −40.9 ± 1.2 | 5.9 ± 0.2 | 5 |
| Navβ2-siRNA | −82.1 ± 1.8 | −6.1 ± 1.1 | 5 | −40.7 ± 1.8 | 6.0 ± 0.8 | 5 |
| Failing heart, INaT | ||||||
| Control siRNA | −81.6 ± 1.7 | −6.7 ± 0.7 | 11 | −40.3 ± 1.5 | 6.4 ± 0.4 | 10 |
| Navβ1-siRNA | −82.2 ± 1.4 | −5.9 ± 0.9 | 9 | −40.2 ± 1.1 | 6.1 ± 0.3 | 10 |
| Navβ2-siRNA | −81.9 ± 1.5 | −6.4 ± 0.7 | 11 | −39.9 ± 1.7 | 5.6 ± 0.4 | 9 |
| Normal heart, INaL | ||||||
| Control siRNA | −81.7 ± 0.5 | −6.2 ± 0.5 | 7 | −37.8 ± 1.2 | 6.1 ± 0.8 | 5 |
| Navβ1-siRNA | −80.2 ± 1.6 | −6.4 ± 0.4 | 5 | −40.1 ± 0.8 | 5.3 ± 0.4 | 5 |
| Navβ2-siRNA | −80.9 ± 1.4 | −6.2 ± 0.8 | 5 | −41.0 ± 0.7 | 5.1 ± 0.6 | 5 |
| Failing heart, INaL | ||||||
| Control siRNA | −80.2 ± 0.8 | −6.3 ± 0.5 | 15 | −38.5 ± 1.9 | 5.4 ± 0.7 | 11 |
| Navβ1-siRNA | −82.0 ± 1.2 | −6.1 ± 0.4 | 19 | −39.2 ± 3.1 | 5.6 ± 0.9 | 6 |
| Navβ2-siRNA | −81.6 ± 1.2 | −6.6 ± 0.4 | 16 | −39.1 ± 1.1 | 5.6 ± 0.5 | 12 |
Values are means ± SE; n, cell number. Steady-state inactivation and steady-state activation (SSI and SSA) parameters were obtained from Na+ current (INa) data fit to the Supplemental Eqs. S2 and S3, respectively. We did not find statistically significant differences between parameters within the experimental groups evaluated by the ANOVA followed by Bonferroni's post hoc test. siRNA, short interfering RNA; INaT, transient Na+ component; INaL, late Na+ component; V1/2G and kG, midpoint and the slope of the respective Boltzmann function underlying the NaCh SSA; V1/2A an kA, midpoint and slope of the relationship of SSI parameters.