Table A3.
Initial conditions for state variables in mathematical model of mouse SAN AP*
| State Variable | Definition | WT | Ankyrin-B+/− |
|---|---|---|---|
| mTTXr | TTX-resistant fast Na+ current (INa,TTXr) activation gate | 0.4013731391 | 0.5175464965 |
| hTTXr | INa,TTXr inactivation gate | 0.2724609414 | 0.1709890012 |
| jTTXr | INa,TTXr slow inactivation gate | 0.02491755567 | 0.02006050186 |
| mTTXs | TTX-sensitive fast Na+ current (INa,TTXs) activation gate | 0.1078937365 | 0.161864092 |
| hTTXs | INa,TTXs inactivation gate | 0.4499459412 | 0.3048035189 |
| jTTXs | INa,TTXs slow inactivation gate | 0.0268422807 | 0.01625136245 |
| d12 | Cav1.2 L-type Ca2+ current (ICaL,1.2) activation gate | 4.556481192e-06 | 1.522040235e-05 |
| f12 | ICaL,1.2 voltage-dependent inactivation gate | 0.9968143283 | 0.9906700529 |
| fca | ICaL calcium-dependent inactivation gate | 0.7649209291 | 0.7686207865 |
| d13 | Cav1.3 L-type Ca2+ current (ICaL,1.3) activation gate | 0.0002036010996 | 0.0005560731373 |
| f13 | ICaL,1.3 voltage-dependent inactivation gate | 0.9809331115 | 0.9590375512 |
| dT | T-type Ca2+ current (ICaT) activation gate | 0.001625076871 | 0.004482631204 |
| fT | ICaT voltage-dependent inactivation gate | 0.426423268 | 0.2744185369 |
| Xr | Rapidly activating K+ current (IKr) activation gate | 0.4043762826 | 0.3367064343 |
| Xri | IKr inactivation gate | 0.925010631 | 0.8997897425 |
| Xs | Slowly activating K+ current activation gate | 0.01271025192 | 0.01089959964 |
| dst | Sustained inward Na+ (Ist) current activation gate | 0.6245901914 | 0.8464766153 |
| fst | Ist inactivation gate | 0.4537962624 | 0.4492530382 |
| Y | Hyperpolarization-activated current (If) activation gate | 0.02800253901 | 0.01852389239 |
| Oi | Transient outward K+ current (Ito) inactivation gate | 0.6106878506 | 0.4978937269 |
| Oa | Activation gate for Ito and Isus | 0.004626741836 | 0.006270214103 |
| Ro | Ryanodine receptor (RyR) open state | 7.577231176e-08 | 6.414963718e-08 |
| Ri | RyR inactivated state | 2.121940549e-08 | 1.757603047e-08 |
| Rri | RyR resting-inactivated state | 0.2154275978 | 0.2124565019 |
| Rr | RyR resting state | 0.7692198658 | 0.7754111992 |
| [Ca2+]i | Ca2+ concentration in myoplasm (mM) | 3.193034323e-05 | 3.235691602e-05 |
| [Ca2+]JSR | [Ca2+] in junctional sarcoplasmic reticulum (mM) | 0.1189292632 | 0.1631189264 |
| [Ca2+]NSR | [Ca2+] in network sarcoplasmic reticulum (mM) | 1.577923289 | 1.542832819 |
| [Ca2+]ss | [Ca2+] in subspace (mM) | 5.603557083e-05 | 7.408237329e-05 |
| fCMi | Fractional occupancy of calmodulin by Ca2+ | 0.0138611385 | 0.01401896089 |
| fCMs | Fractional occupancy of calmodulin by subspace Ca2+ | 0.02419980623 | 0.0313994341 |
| fTC | Fractional occupancy of troponin Ca2+ site by Ca2+ | 0.006346326788 | 0.006416675037 |
| fTMC | Fractional occupancy of troponin Mg+ site by Ca2+ | 0.1297414046 | 0.1266803519 |
| fTMM | Fractional occupancy of troponin Mg+ site by Mg+ | 0.7688005798 | 0.7715097855 |
| fCQ | Fractional occupancy of calsequestrin by JSR Ca2+ | 0.120498404 | 0.1601843848 |
| [Na+]i, mM | Na+ concentration in myoplasm | 8.11828204 | 7.785938742 |
| [K+]i, mM | K+ concentration in myoplasm | 139.8850767 | 140.2183952 |
| Vm, mV | Transmembrane potential | −64.52369393 | −58.40912806 |
*
Single cell underwent spontaneous activity for 200 s. Model equations for mouse SAN cell are found in original publication (23).