FIGURE 6.

Ca²⁺ sparks and Ca²⁺ bursts activated by NAADP-AM in PASMCs. A, the upper panel is a surface plot of Ca²⁺ fluorescence immediately after the addition of NAADP-AM showing Ca²⁺ sparks originating from two separate sites (marked 1 and 2) and the diffuse increase in cytosolic [Ca²⁺]. The lower panel shows the time course of ΔF/F₀ recorded at sites 1 and 2 and the mean ΔF/F₀ across the image. B, the upper panel is a surface plot of a Ca²⁺ burst activated by NAADP in a different cell. The lower panel shows the time course of ΔF/F₀ recorded at site 3.