Figure 7. Parameters reflecting Ca²⁺ release in isolated rat ventricular myocytes.

A, control (left) and post-MI (right) APs were applied to myocytes after a loading protocol of eight 100 ms steps to +10 mV. B, kinetically corrected intracellular Ca²⁺ transients triggered by control and post-MI APs. These data were used to calculate the SR release flux, F_rel, according to the equation: d[Ca²⁺]_i/dt =F_rel+F_pump+F_leak+Σd[CaL]/dt (see Methods). C, SR release flux, F_rel, triggered by short control and long post-MI APs. D, rate of unloaded cell shortening, d(CS)/dt, triggered by control and post-MI APs.