Figure 6

BSA-induced [Ca²⁺] _i rises under clamped membrane potential (V _m ) or intracellular pH (pH _i ). (A-C) Representative recordings in different [K⁺]_o as indicated, without (A) or with (B and C) 1 μM valinomycin in the bath to "clamp" the membrane potentials to -40 mV ([K⁺]_o = 24 mM) or -20 mV ([K⁺]_o = 54 mM). (D) Averaged peak ΔF/F₀ in responsive cells under various [K⁺]_o, with or without valinomycin. (E, F) Peak [Ca²⁺]_i rise amplitude (E) and response percentages (F) induced by 5 mg/ml BSA without pH_i clamp or under pH_i clamp. Numbers of tested cells are indicated within the bars. *, P < 0.05 compared to the no pH_i clamp condition.