General parameters¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| r_SR | 6 | μm | Radius of SR |
| r_SL | 10.5 | μm | Radius of sarcolemma |
| V_SR | 0.0903 | pL | SR volume |
| V_NSR | 0.9V_SR | pL | Network SR volume |
| V_JSR | 0.1V_JSR | pL | Junctional SR volume |
| V_subSR | 0.046 | pL | Sub-SR volume |
| V_subSL | 0.137 | pL | Sub-sarcolemma volume |
| V_myo | 3.944 | pL | Cytosolic volume |
| A_cap | 1385.44 | μm² | Cell membrane area |
| C_m | 1 | μFcm⁻² | Cell membrane capacitance |
| ca_o | 1796 | μM | External calcium concentration |
| na_o | 154578 | μM | External sodium concentration |
| k_o | 5366 | μM | External potassium concentration |
[ATP] | 5000 | μM | ATP concentration |
| V_T | 26.7 | mV | Thermal voltage |
Calcium diffusion¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| ΣTrpn | 35 | μM | Total troponin content |
| Km_Trpn | 0.5 | μM | Half-saturation Ca concentration |
| ΣCmdn | 30 | μM | Total calmodulin content |
| Km_Cmdn | 2.38 | μM | Half-saturation Ca concentration |
| D_ca | 7 | μm²ms⁻¹ | Calcium diffusion rate |
| dx | 0.1 | μm | Discretization distance |
| fracTnIp_0 | 0.062698 | - | Baseline effect of PKA on Troponin |
Endoplasmic reticulum¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| k_RyR | 20 | 1/s | RyR permeability |
| kapos_RyR | 1000 | 1/s | RyR state transition rate |
| kaneg_RyR | 160 | 1/s | RyR state transition rate |
| Vmax_SR | 999.6 | μM/s | SERCA reaction rate |
| Kmf_SR | 0.5 | μM | Calcium affinity for SERCA |
| Kmr_SR | 7000 | μM | Calcium affinity for SERCA |
| kSR_leak | 0.005 | 1/s | SR leak rate |
| ktrCa_SR | 50 | 1/s | Calcium diffusion rate from NSR to JSR |
| ΣCSQN$ | 24750 | μM | Calsequestrin concentration |
| Km_csqn | 800 | μM | Calcium affinity for calsequestrin |
| fracPKA_PLBo | 00.920245 | - |
Sarcolemmal sodium channels¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| G_Na | 12.8 | mS/μF | Fast sodium channels conductance |
| G_Nab | 0.0026 | mS/μF | Background sodium channels conductance |
Sarcolemmal potassium channels¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| G_K1 | 0.0515 | mS/μF | Potassium channels conductance |
| G_t | 0.1 | mS/μF | Transient outward potassium channels conductance |
| G_Ks | 0.05 | mS/μF | Potassium channels conductance |
| τ_nKs | 750 | ms | Potassium channels time scale |
| G_Kr | 0.06 | mS/μF | Potassium channels conductance |
| k_fIKr | 23.761 | 1/s | Potassium channels transition rate |
| k_bIKr | 36.778 | 1/s | Potassium channels transition rate |
| G_f | 0.021 | mS/μF | Funny current conductance |
| f_Na | 0.021 | - | Funny current sodium fraction |
| f_is | 0.706 | - | Transient outward gating variable |
Sarcolemmal calcium channels¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| fNaCa | 1 | - | |
| kNaCa | 2.268 * 10⁻¹⁶ | μAμF⁻¹μM⁻⁴ | |
| dNaCa | 10⁻¹⁶ | μM⁻⁴ | |
| gNaCa | 0.5 | - | |
| G_CaL | 6.3 * 10⁻⁵ | m³s⁻¹F⁻¹ | |
| τ_fca | 10 | ms | |
| g_CaT | 0.2 | mSμF⁻¹ | |
| g_Cab | 0.0008 | mSμF⁻¹ | |
| ICascale_0 | 0.95 | - | |
| fracLCCbp_0 | 0.250657 | - | |
| fracLCCbpISO | 0.525870 | - |
Sarcolemmal Na-K pump¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| Imax_NaK | 2.7 | μA/μF | Maximal rate of Na-K pump |
| KmNai_NaK | 18600 | μM | |
| KmKo_NaK | 1500 | μM | |
| nNaK | 3.2 | - | Hill coefficient for sodium of Na-K pump |
B1AR¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| PKACI_0 | 0.0734 | - | Basal PKACI activity |
| PKACI_act | 0.1995 | - | Activated PKACI activity |
| PKACI_KM | 0.0139 | μM | PKACI sensitivity to ISO |
| PKACII_0 | 0.1840 | - | Basal PKACII activity |
| PKACII_act | 0.3444 | - | Activated PKACII activity |
| PKACII_KM | 0.0103 | μM | PKACII sensitivity to ISO |
| PP1_0 | 0.8927 | - | Basal PP1 activity |
| PP1_act | 0.0492 | - | Activated PP1 activity |
| PP1_KI | 0.00637 | μM | PP1 sensitivity to ISO |
| PLBp_0 | 0.0824 | - | Basal PLB phosphorylation |
| PLBp_act | 0.7961 | - | Activated PLB phosphorylation |
| PLBp_KM | 0.00597 | μM | PLB phosphorylation sensitivity to ISO |
| PLBp_n | 1.8167 | - | Hill coefficient for ISO |
| PLMp_0 | 0.1172 | - | Basal PLMp phosphorylation |
| PLMp_act | 0.6645 | - | Activated PLMp phosphorylation |
| PLMp_KM | 0.00823 | μM | PLM phosphorylation sensitivity to ISO |
| PLMp_n | 1.35784 | - | Hill coefficient for ISO |
| TnIp_0 | 0.0669 | - | |
| TnIp_act | 0.7524 | - | |
| TnIp_KM | 0.007913 | μM | |
| TnIp_n | 1.6736 | - | |
| LCCap_0 | 0.2205 | - | |
| LCCap_act | 0.2339 | - | |
| LCCap_KM | 0.00726 | μM | |
| LCCbp_0$ | 0.2517 | - | |
| LCCbp_act | 0.2461 | - | |
| LCCbp_KM | 0.00695 | μM | |
| KURp_0 | 0.4390 | - | |
| KURp_act | 0.2563 | - | |
| KURp_KM | 0.00557 | μM | |
| RyRp_0 | 0.2054 | - | |
| RyRp_act | 0.2399 | - | |
| RyRp_KM | 0.0075135 | μM |
CaMKII¶
| Parameter | Value | Units | Description |
|---|---|---|---|
| v_CaMK | 3 | Hz | CaMK-CaM binding rate |
| r_CaMKO | 0 | - | Oxidized CaMK-CaM binding ratio |
| r_CaMKP | 0 | - | Phosphorylated CaMK-CaM binding ratio |
| kb_CaMKP | 1/3 | Hz | Dissociation rate of CaMKP |
| kfa2_CaMK | 0.2650 | - | Maximal CaM-Ca2 binding ratio |
| kfa4_CaMK | 0.1636 | - | Maximal CaM-Ca4 binding ratio |
| kfb_CaMK | 0.001 | - | Basal CaMK-CaM binding ratio |
| kmCa2_CaMK | 0.7384 | μM | Half-saturation calcium concentration for CaM-Ca2 binding |
| kmCa4_CaMK | 1.2513 | μM | Half-saturation calcium concentration for CaM-Ca4 binding |
| kphos_CaMK | 5 | Hz | Autophosphorylation rate |
| kdeph_CaMK | 1/6 | Hz | Dephosphorylation rate |
| k_P1P2 | 1/60 | Hz | Second autophosphorylation rate |
| k_P2P1 | 1/15 | Hz | Second dephosphorylation rate |
| kox_CaMK | 291 | Hz/mM | Oxidation rate |
| krd_CaMK | 1/45 | Hz | Reduction rate |