Fig. 1. Effect of DTT on VRAC chloride current measured in wild-type HEK293 cells. (A) Whole-cell chloride currents measured in control conditions (iso, 340 mOsm.l^-1) in the absence or presence of DTT (2mM) and after replacing the bath with a hypotonic solution (hypo, 270 mOsm.l^-1) containing or not DTT (2mM, 5 min). Cells were held at −50 mV, and 400 ms pulses from −100 to +100 mV were applied in 20 mV increments. Exact compositions of pipette and bath NMDGCl solutions are given in [14]. (B) I/V curve of the chloride currents (n=14) triggered by hypotonic shock recorded as in A and measured in the absence and presence of DTT (2mM). I/V relationships are expressed as the mean current amplitudes measured at all potentials at 6-10 ms after the pulse onset. (C) Comparison of the VRAC conductances slope measured after hypotonic solution exposure in the absence (hypo) or presence of DTT (2mM, hypo DTT). Conductances were calculated between +40 to +80 mV from 14 individual cells (Wilcoxon test was used, ***p< 0.0001).