You are here: Home / Exposures / Koivumaki, Takalo, Korhonen, Tavi, Weckstrom, 2009 / Modelling Sarcoplasmic Reticulum Calcium APTase and its Regulation in Cardiac Myocytes

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Component: environment

t_modulo = time mod 1000

Component: general_parameters

Component: action_potential

V = rest + A {(1 - (ⅇ^{\frac{- t_modulo}{t1}}))}^{p} ⅇ^{\frac{- t_modulo}{t2}} (1 - (\frac{{t_modulo}^{10}}{{A1}^{10} + {t_modulo}^{10}}))

Component: calcium_input

tcalcium = \{\begin{matrix} 0 if t_modulo - 1.2 ≦ 0 \\ t_modulo - 1.2 otherwise \end{matrix} Ca_input = Ca_amp {(1 - (ⅇ^{\frac{- tcalcium}{Ca_tau1}}))}^{Ca_pow} ⅇ^{\frac{- tcalcium}{Ca_tau2}}

Component: NCX_current

INaCa = \frac{kNaCa}{({KmNa}^{3} + {Na_o}^{3}) (KmCa + Ca_o) (1 + ksat ⅇ^{\frac{(eta - 1) V F}{R T}})} (ⅇ^{\frac{eta V F}{R T}} {Na_i}^{3} Ca_o - (ⅇ^{\frac{(eta - 1) V F}{R T}} {Na_o}^{3} Ca_cyt))

Component: serca_parameters

EC_50_fwd = (Kmf_PLBKO + \frac{Kmf_PLB PSR PLB_dephosph}{1}) (1 + 0.27 CaMKII_reg) EC_50_rev = Kmr_PLBKO - (\frac{Kmr_PLB PSR PLB_dephosph}{1})

Component: transition_parameters

br_cyt_serca = 1000 br_serca_sr k_cyt_serca = br_cyt_serca (1 + 0.7 CaMKII_reg) k_serca_cyt = {EC_50_fwd}^{2} br_cyt_serca k_serca_sr = br_serca_sr (1 + 0.7 CaMKII_reg) k_sr_serca = \frac{br_serca_sr}{{EC_50_rev}^{2}}

Component: calcium_fluxes

J_cyt_serca = k_cyt_serca {Ca_cyt}^{2} (SERCA_TOT - Ca_serca) - (k_serca_cyt Ca_serca) J_serca_sr = k_serca_sr Ca_serca - (k_sr_serca {Ca_NSR}^{2} (SERCA_TOT - Ca_serca)) J_up = J_cyt_serca - J_serca_sr

Component: calcium_buffering

B_i = {(1 + \frac{CaM_tot Km_CaM}{{(Km_CaM + Ca_cyt)}^{2}})}^{- 1} J_LTRPN = kltrpn_pos Ca_cyt (LTRPN_tot - LTRPN) - (kltrpn_neg LTRPN)

Component: differential_equations

\frac{d}{d time} (Ca_cyt) = B_i ((\frac{INaCa Acap C_m}{2 V_myo F} - J_cyt_serca) + J_leak + Ca_input - J_LTRPN) \frac{d}{d time} (LTRPN) = kltrpn_pos Ca_cyt (LTRPN_tot - LTRPN) - (kltrpn_neg LTRPN) \frac{d}{d time} (PLB_dephosph) = kplb_pos (PLB_tot - PLB_dephosph) - (kplb_neg {(CaMKII_reg + PKA_reg)}^{2} PLB_dephosph) \frac{d}{d time} (Ca_serca) = J_cyt_serca - J_serca_sr

Source: Derived from workspace Koivumaki,2009 at changeset 882b85019849.

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