Fig. 1.

NAADP induces calcium release in undifferentiated C2C12 cells. (A) Example traces of calcium release induced by 1 or 10 μM ryanodine (first arrow) followed by 100 μM ATP (second arrow). (B) Bar graph (mean with SEM; n = 25–40 cells) representing the change in cytosolic calcium following addition of ryanodine or ATP. (C) Example traces of calcium release induced by 50, 100, 500, and 1 μM NAADP-AM. Arrows indicate addition of NAADP-AM. (D) Bar graph (mean with SEM; n = 12–16 cells) representing the change in cytosolic calcium following addition of NAADP-AM.