Fig. 2. Resting and inactivated block of Na+channels by duloxetine in human embryonic kidney cells expressing neuronal Nav1.7 and Nav1.4 isoforms. (A ) Traces of wild-type hNav1.7 currents shown illustrate the resting block by 3 μm duloxetine at the holding potential of −140 mV, whereas traces shown (B ) show the inactivated block by 3 μm duloxetine after a conditioning pulse of −70 mV for 10 s. Pulse protocols are shown in the inset . Currents were evoked every 30 s by a 5-ms test pulse at +30 mV before and after duloxetine wash-in. Block of peak current by duloxetine reached its steady state generally within 3–5 min, and this block was readily reversible after drug wash-out, usually within 5 min. (C ) Traces of wild-type rNav1.4 currents shown illustrate resting block by 3 μm duloxetine, whereas traces shown on D show inactivated block by 3 μm duloxetine. Current traces in four panels were recorded from separate cells. h = human.