Fig. 3.
Changes in TTX-R activation induced by ET-1 are prevented by an ETA receptor antagonist. A family of control currents recorded in the same cell is shown before (A), 10 min after continuous exposure to the ETA receptor antagonist BQ-123 (1 μm) (B), and after 10 min of additional exposure to BQ-123 (1 μm) plus ET-1 (10 nm) (C). Recording conditions were identical to those described in Figure 1. D, Boltzmann functions for the normalized peak conductance versus test potential from current data shown in A–C. Neither the activation midpoint nor the slope were modified by ET-1 in the presence of BQ-123 or by BQ-123 alone.