Fig. 7.

Effect of 2-APB on Ca²⁺ waves induced by the flash photolysis of caged-IP₃. The Ca²⁺ response of the SMC induced by the repetitive flash photolysis (0.2-s exposure; lightning bolts) of caged-IP₃ in lung slices incubated with 100 μM 2-APB (A) or zero extracellular Ca²⁺ (0-Ca²⁺; B) for 3 min is shown. Summary of the changes in SMC Ca²⁺ signaling (peak florescence intensity) induced by IP₃ in the presence of 2-APB (C) or absence of extracellular Ca²⁺ (D) is shown. Exposure to 2-APB virtually abolished the Ca²⁺ response to IP₃, whereas the removal of extracellular Ca²⁺ had little effect on IP₃-induced Ca²⁺ signaling. Data represent the means ± SE from 5 different slices from 2 mice.