ISO-dependent leak is attenuated by NOS inhibitor, L-NAME.

A) The leak-dependent shift of Ca2+ from the cytosol to the SR. Each point represents a loading protocol (from low to high [Ca]SRT; resting, 1 field stimulation, 0.25 Hz, 0.5 Hz and 1 Hz stimulation, respectively). B) The SR Ca2+ leak (right) in [Ca]SRT matched data (left, n = 10–14). C) The [Ca]SRT (right) needed to induce the same SR Ca2+ leak (left) in leak matched data (left, n = 11–17). *Statistically different from control, #different from ISO (t-test, p<0.05).