FIGURE 5.

Activation of local Ca²⁺ events by NAADP-AM in PASMCs. A, representative confocal line scan images from three different cells showing local and global Ca²⁺ events elicited by NAADP-AM (0.5 μm). The upper and lower panels show the progressive increase in cytosolic [Ca²⁺], spark frequency, localized Ca²⁺ bursts, and global Ca²⁺ release. The lower panel illustrates a solitary Ca²⁺ burst that was not associated with global Ca²⁺ release. Blue circles denote the positions of discernible local Ca²⁺ events, red bars denote repetitive burst, and yellow bars indicate diffuse increases in cytosolic [Ca²⁺]. B, a combined figure showing the spark frequency (number of sparks/100 μm/cell) distribution and the averaged global Ca²⁺ transient (F/F₀; red line and symbols) generated from 23 different cells. The asterisk indicates the value is significantly lower (p < 0.05) than that of NAADP alone.