Fig. 7
From: HCO3 −-dependent transient acidification induced by ionomycin in rat submandibular acinar cells
Effects of extracellular pH (pHo) on the rate of F 340/F 380 increase (Ca2+ influx) stimulated by IM. Experiments were carried out using a HCO3 −-containing solution. a 5 μM IM: increases in F 340/F 380 after re-introduction of Ca2+ at pHo of 8.0 and 6.8. Increases in F 340/F 380 were enhanced at a pHo of 8.0. b 1 μM IM. Increases in F 340/F 380 after re-introduction of Ca2+ at pHo of 8.0 and 6.8. Increases in F 340/F 380 were not affected by pHo. c Rates of the F 340/F 380 increase were plotted against pHo. Upon stimulation with 5 μM IM, the rates increased with increasing pHo. However, upon stimulation with 1 μM IM, the rates remained almost constant with increasing pHo. The rates of F 340/F 380 increase obtained in HCO3 −-free solution (data calculated from Fig. 8) are also plotted in this figure