Table II.
Regional Differences in the Expression of Mouse Ventricular K+ Currents
| Source | Ipeak | Ito,f | Ito,s | IK,slow | Iss | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Apex | ||||||||||
| τdecay (ms) | — | 59 ± 2 | — | 1174 ± 17 | — | |||||
| Density* (pA/pF) | 57.2 ± 3.5 | 34.6 ± 2.6 | — | 17.2 ± 1.1 | 5.5 ± 0.4 | |||||
| Percent Ipeak | — | 60 | — | 30 | 10 | |||||
| n | 35 | 35 | — | 35 | 35 | |||||
| Septum | ||||||||||
| Cells with Ito,f | ||||||||||
| τdecay (ms) | — | 53 ± 2 | 258 ± 15 | 1180 ± 45 | — | |||||
| Density* (pA/pF) | 30.9 ± 1.5 | 6.8 ± 0.5 | 7.4 ± 0.7 | 12.5 ± 0.6 | 4.3 ± 0.3 | |||||
| Percent Ipeak | — | 22 | 24 | 40 | 14 | |||||
| n | 22 | 22 | 22 | 22 | 22 | |||||
| Cells lacking Ito,f | ||||||||||
| τdecay (ms) | — | — | 194 ± 11 | 1143 ± 64 | NA | |||||
| Density* (pA/pF) | 20.5 ± 2.5 | — | 5.4 ± 0.9 | 10.4 ± 1.5 | 4.8 ± 0.4 | |||||
| Percent Ipeak | — | — | 26 | 51 | 23 | |||||
| n | 6 | — | 6 | 6 | 6 |
*
Current densities were determined from analyses of records obtained on depolarization to +40 mV from a holding potential of −70 mV; all values are means ± SEM.