Figure 7. Effect of caffeine and 4-CmC on the time course of free calcium and the rate of release.

A, free calcium concentration (a, c, e and g) and calculated rate of release R (b, d, f and h) in a cut muscle fibre depolarized to 0 mV for 10 or 20 ms (see pulse scheme at the bottom) before and after application of 5 μM 4-CmC. B, free calcium concentration (a, c, e and g) and calculated rate of release R (b, d, f, and h) before and after application of 0.5 mM caffeine. In both A and B, traces a-d are from one experiment with 15 mM internal EGTA