The kinetics of BK channels affects not only the amplitude of STOCs but also the rise time of STOCs. In this study, we found that signal mass rise time shows no difference compared with TTODSTOC (Fig. 1). Because signal mass is an integrated amount of Ca2+ being released during Ca2+ sparks, its value should continue to increase as long as RYRs in the spark site are open. The similarity between signal mass rise time and TTODSTOC suggests that the kinetics of the BK channel plays a role in determining the duration of STOC rise. On the other hand, it suggests that the open time of RYRs in the spark sites is another critical variable affecting the rise time of a STOC.
