Figure 2. Activation of ionic currents by IP₃, IP₄ and thapsigargin in CHO(CCE1) cells.

The internal solution contained 115 mM Cs⁺. IP₃ (10 μM) was dialysed in the presence of 10 mM BAPTA (A, IP₃/BAPTA) and 400 nM free Ca²⁺ (B, IP₃/400 nM ${\text{Ca}}_{\text{i}}^{\text{2+}}$). Thapsigargin (1 μM) was applied to cells dialysed with 10 mM EGTA (C, TG/EGTA). IP₄ (20 μM) was dialysed with 10 mM EGTA (D, IP₄/EGTA). Same external solution as in Fig. 1.