ATX-II enhances hNav1.5 currents in stably transfected HEK cells. hNav1.5 currents were elicited by a 50 ms voltage step from the holding potential of -100 mV to -20 mV, applied every 20 sec, using whole-cell voltage clamp technique (bath solution contains TEA and pipette solution contains CsF). A. Time course, showing the effect of 0.05 nM, 0.5 nM, 5 nM and 50 nM ATX-II (ab141870) on the current area, indicating a dose-dependent slowing of the hNav1.5 inactivation. B. Superimposed traces of hNav1.5 currents under control conditions and after 4-6 min perfusion with 0.05 nM, 0.5 nM, 5 nM and 50 nM ATX-II, as indicated.