Figure 2.

Gd³+ sensitivity and anion selectivity of swelling-induced phloretin-insensitive whole-cell currents. (A) Representative trace of Gd³+ sensitivity of currents recorded from a C127i cell dialyzed with ATP-free pipette solution during application of alternating pulses from 0 to ±25 mV or of step pulses from −50 to +50 mV in 10-mV increments. (B) Effects of Gd³+ (30 μM), NPPB (100 μM), and SITS (100 μM) on the instantaneous currents recorded upon application of step pulses of ±25 mV. All currents measured in the presence of these drugs were normalized to the respective currents measured before drug application. Also, currents were corrected for background currents. The SEM values are shown by vertical bars. (C) Representative instantaneous current-voltage relationships demonstrating the anion selectivity of this channel. All currents were recorded from a C127i cell exposed to a hypotonic solution containing 300 μM phloretin and 100 mM NaCl (open circles) or TEA-Cl (closed circles) or sodium gluconate (closed triangles). Similar data were obtained in five cells.