Fig. 3.
Lidocaine inhibits HCN4 channel currents. A, sample currents from HEK 293 cells expressing mHCN4 channel construct evoked by hyperpolarizing voltage steps from −40 to −120 mV before and during exposure to lidocaine (100 μM); conditioning voltage steps (6–14 s) were followed by a step to −90 mV for tail current analysis. B, steady-state I-V curves from currents at the end of the voltage steps (top), and activation curves were determined from tail currents (bottom) under control conditions (■) and during exposure to lidocaine (▵). C. Summary data showing averaged (± S.E.M.) current inhibition (percentage from control; left) and shift in half-activation potential (V1/2; right) evoked by lidocaine metabolite MEGX for each of the indicated HCN channel constructs. *, P < 0.05 versus control.