Fig. 2. Ca²⁺-activated Cl^- current and Ca²⁺-activated nonselective cationic current in HNSCCs.

(A~C) Representative I/V curves obtained by ramplike pulses used CsCl pipette solution with 600 nM free Ca²⁺ activity in the three types of cell lines. Steady-state Ca²⁺-activated conductance (black I/V curves in each panel) was decreased by about half after applying 10 M T16A, a selective inhibitor of Ano-1 (I/V curves in red). The remained conductance, especially the inward current, was further decreased by replacing extracellular Na⁺ with NMDG⁺ (T16A+NMDG, I/V curves in green). (D) Summary of normalized inward current densities at -60 mV. The inward current density (pA/pF) was normalized (%) to the control steady-state in each cell. The remained current after T16A (red) and Na⁺ removal (green) are averaged. (E) Summary Ano-1 current densities (pA/pF) at -60 mV in HNSCCs. Ano-1 current was obtained by subtracting T16A-resistent current from control in each cell, and the plotted dots indicate data from individual cell.