Figure 2.
Effect of FPL on SR Ca2+ release. (A) Ca2+ release immediately before (Left column) and during the first depolarizing pulse (Right column) after application of 10 μM FPL. From Top to Bottom: voltage protocols, confocal line-scan images, normalized spatially averaged OG-5N signals (F/F0), ICa, and superimposed peak normalized ICa (black traces) and SR Ca2+ release function (fr, red traces). Vertical and horizontal axes of line-scan images are axes of space and time, respectively. Smooth lines in the F/F0 panels represent fs and red lines in the Bottom panels represent fr generated by subtracting fs from the ΔF/F0 traces. (B) Latency distribution of Ca2+ spikes (n = 376) elicited in 10 myocytes during the first and second pulses after application of FPL (10 μM). The red and blue lines are the scaled latency distributions of the first openings and reopenings, respectively, of Ca2+ channel of Fig. 1C.