Figure 1
From: Multiple mechanisms mediating carbon monoxide inhibition of the voltage-gated K+ channel Kv1.5
CO inhibits recombinant hKv1.5. (a) Time-series plot (generated by repeated step depolarizations from −80 to +50 mV (100 ms duration, 0.2 Hz)) obtained from a HEK293 cell stably expressing human Kv1.5 (hKv1.5). Plot shows normalized peak current amplitudes. For the period indicated by the horizontal bar, the cell was exposed to 30 μM CORM-2. (b) As in panel (a), except this cell was exposed to 30 μM iCORM (inactive breakdown product of CORM-2), as indicated. (c) Example currents from the plotted time series evoked before and during application of CORM-2 (upper) and iCORM (lower). (d) Left, currents evoked in a HEK293 cell expressing hKv1.5 before and during exposure to 30 μM CORM-2, as indicated. Currents were evoked by step-depolarizations from −60 to +80 mV. Right, Mean (±S.E.M., n=6) current–density versus voltage relationships obtained before (open symbols) and during (solid symbols) application of 30 μM CORM-2. (e) Concentration–response curve for CORM-2 inhibition of hKv1.5. Each point is the mean (±S.E.M., n=3–17 cells in each case) fractional inhibition caused by CORM-2. Data fit yields IC50 of 23 μM
