Different Densities of Na-Ca Exchange Current in T-Tubular and Surface Membranes and Their Impact on Cellular Activity in a Model of Rat Ventricular Cardiomyocyte

Figure 1

Simulation of Ca²⁺ concentration changes in the submembrane spaces (t-tubular: , surface: ), cytosol (), and network compartment of SR () in unstimulated cell under different values of t-tubular fraction of Na-Ca transporters (). of 0.48 and 0.93, respectively, corresponds to -ratio of 1.7 and 25 (see Section 2.2). of 0.78 represents the original value in the model [19]. The original adjustment of membrane capacitances and extracellular ion concentrations in the model ( = 65.02 pF, = 34.98 pF, = 140 mM, = 5.4 mM, = 1.2 mM) was preserved.