Figure 6.

Activation of a nonselective cation channel in MDM by gp120 but not by MIP-1β or SDF-1α. Currents were recorded by using a pipette solution in which Cs⁺ replaced K⁺, aspartate was substituted for Cl⁻, and the cell was voltage-clamped at the calculated E_Cl of −45 mV. NPPB (10 μM) was added to block any residual Cl⁻ current. Cells were stimulated with JRFL gp120 (A), IIIB gp120 (B), MIP-1β (C), and SDF-1α (D). At the peak of gp120-activated currents, the bath solution was replaced with a low sodium solution (30 mM) as indicated by the bars (A and B). The reversal potentials for currents evoked by gp120 were determined in normal (squares) and low sodium (circles) bath solutions (lower panels of A and B).