Figure 8. Inhibition of SOCE by 2-APB in rat parotid acinar cells.

A, B. 2-APB (20 µM) blocked the entry of Ca²⁺ into Fura2-loaded cells in which Ca²⁺ stores were depleted by the addition of TG (1 µM) (Figure 8A) or carbachol (10 µM) (Figure 8B) to cells in Ca²⁺-free solution. Vehicle was added to the control cells. C. 2-APB blocks Ca²⁺ entry after depletion of Ca²⁺ stores by TG (1 µM) and after the increase in [Ca²⁺]_i produced by addition of 1 mM CaCl₂ to store-depleted cells. After depletion of Ca²⁺ stores and the return of [Ca²⁺]_i to baseline levels, 2-APB (20 µM) was added (gray line) 1 min prior to the addition of 1 mM CaCl₂. After the peak increase in Ca²⁺ produced by addition of 1 mM CaCl₂ after store-depletion under control conditions (black line), 2-APB produced an immediate decrease in the level of [Ca²⁺]_i. The ordinate axis is 340/380-nm Fura-2 fluorescence excitation ratio. Shown are individual traces of one experiment, which are representative of at least 3 experiments.