Inhibition of the human RBC Cl-conductance by NS3623.

(A) CCCP-mediated pH changes and the corresponding RBC membrane potentials (ordinate axis) recorded on incubation of human RBCs with a valinomycin concentration of 50 nM (addition at first arrow) and increasing concentrations of NS3623 (0, 0.5, 2.0, and 8.0 μM). Experiments were terminated by the addition of TX-100 (second arrow) to determine the intracellular pH, which corresponds to a membrane potential of 0 mV. Hematocrit, 1.6%, 37°C. (B) Chemical structure of NS3623 and normalized Cl-conductances versus the concentration of NS3623. The curve represents the best fit to a Hill-type equation.