Fig. 3.

Pranlukast inhibits volume-regulated anion channel (VRAC) currents. A: whole cell currents from human embryonic kidney 293 (HEK293) cells were measured using a step protocol from −120 to +120 mV, with 20 mV steps. Cells were exposed to hypotonic bath and hypotonic bath + 3 µM pranlukast. B: dose-dependent inhibition of VRAC with pranlukast from whole cell patch-clamp electrophysiology maximum efficacy at 3 µM = ~50%; n ≥ 4). C: whole cell currents from HEK293 cells were measured using a ramp protocol from −100 to +100 mV. Cells were exposed to hypotonic bath and hypotonic bath + 3 µM pranlukast. D: analysis of VRAC currents with 3 µM pranlukast at −100 and +100 mV by application of the voltage-ramp protocol. ns, Not significant. E: exemplar time course of VRAC activation under hypotonic solution exposure, 3 µM pranlukast (P-kast), and wash (hypo) treatment. F: 3 µM pranlukast-dependent current inhibition time constant (mean ± SE τ = 62 ± 16 s; n = 7).