Figure 3. Effects of Ni²⁺, nifedipine and hyper-potassium solution on the ET1-induced Ca²⁺ response in a ST.

Ca²⁺ response to ET1 (10⁻⁷ m) in the presence of 1 mm Ni²⁺ (A) or nifedipine (10⁻⁶ m; B). C, representative recording of the Ca²⁺ response to 100 mm K⁺ perfusion and subsequent response to ET1 perfusion (10⁻⁷ m). Arrows in A–C indicate the time of measurement used for the calculation of the percentage changes in ratios expressed in Fig. 4.