Table 1.
Kv and Kir Currents in Swim-trained and Untrained Akt1−/−, WT+Vehicle, icaPI3Kα+Vehicle and icaPI3Kα+TCN LV Myocytes.*
| LV Cells | Cm (pF) | IK,peak | Ito,f | IK,slow | Iss | IK1 | |
|---|---|---|---|---|---|---|---|
| Akt1−/− untrained | 141 ± 6 | ||||||
| (n=23) | τ (ms) | — | 89 ± 6 | 1597 ± 112 | — | — | |
| Amplitude (pA) | 5289 ± 436 | 2103 ± 225 | 2118 ± 194 | 1067 ± 68 | −1276 ± 80 | ||
| Density (pA/pF) | 37.2 ± 2.5 | 14.7 ± 1.4 | 14.9 ± 1.1 | 7.6 ± 0.5 | −8.4 ± 0.9 | ||
| Akt1−/− trained | 141 ±7 | ||||||
| (n=20) | τ (ms) | — | 75 ± 6 | 1303 ± 61 | — | — | |
| Amplitude (pA) | 7235 ± 523# | 3387 ± 385# | 2557 ± 198 | 1291 ± 91‡ | −2471 ± 139* | ||
| Density (pA/pF) | 54.3 ± 5.4# | 25.9 ± 3.4# | 19.2 ± 2.1 | 9.3 ± 0.6‡ | −12.5 ± 0.6* | ||
| WT+Vehicle | 181 ± 9 | ||||||
| (n=33) | τ (ms) | — | 121 ± 9 | 1097 ± 95 | — | — | |
| Amplitude (pA) | 11485 ± 659 | 4159 ± 314 | 5399 ± 391 | 1599 ± 91 | −2677 ± 173 | ||
| Density (pA/pF) | 67.2 ± 4.0 | 24.8 ± 2.1 | 31.1 ± 2.0 | 9.1 ± 0.4 | −14.9 ± 1.0 | ||
| icaPI3Kα+Vehicle | 177 ± 9 | ||||||
| (n=24) | τ (ms) | — | 109 ± 55 | 981 ± 55 | — | — | |
| Amplitude (pA) | 16087 ± 1139* | 6424 ± 734# | 6780 ± 471‡ | 1837 ± 104 | −3457 ± 284‡ | ||
| Density (pA/pF) | 92.2 ± 5.9# | 38.8 ± 4.4# | 41.2 ± 3.1‡ | 11.2 ± 0.7 | −19.1 ± 1.4‡ | ||
| icaPI3Kα+TCN | 171 ± 6 | ||||||
| (n=21) | τ (ms) | — | 90 ± 36 | 949 ± 30 | — | — | |
| Amplitude (pA) | 15394 ± 903* | 6199 ± 493* | 6563 ± 367‡ | 1751 ± 94 | −3077 ± 188‡ | ||
| Density (pA/pF) | 96.1 ± 6.0* | 35.0 ± 2.5# | 37.4 ± 2.1‡ | 10.0 ± 0.5 | −18.8 ± 1.4‡ | ||
*
All values are means ± SEM. Kv and Kir current amplitudes/densities reported here were determined at +40 mV and −120mV, respectively. Measured K+ current amplitudes/densities in swim-trained and untrained Akt1−/− LV myocytes were compared and K+ currents in icaPI3Kα+Vehicle and icaPI3Kα+TCN LV myocytes were both compared to results from WT+Vehicle animals.
Values that are significantly (‡P<0.05, #P<0.01, *P<0.001) different are indicated.
Kv indicates voltage-gated K+ currents; Kir, inwardly rectifying K+ currents; TCN: triciribine; Cm, cell membrane capacitance; τ, time constant of inactivation.