Fig. 4

Effects of 100 μM acetazolamide (ACZ, an inhibitor of carbonic anhydrase) on pH_i changes induced by IM. a 5 μM IM. The addition of ACZ and the further addition of 5 μM IM have no effect on pH_i in Ca²⁺-free solution. The re-introduction of Ca²⁺ induced a small pH_i decrease followed by a gradual pH_i increase. b τ plot of a. The pH_is for 4 min after the re-introduction of Ca²⁺ were used. The τ plot revealed that the pH_i increase after re-introduction of Ca²⁺ consisted of the single component with ACZ. c 1 μM IM. ACZ abolished the pHi changes induced by 1 μM IM