Figure 5. Effects of Kv7 channel modulators on cerebral artery SMC outward K⁺ currents.

A. Representative traces of outward K⁺ currents in cerebral artery VSMCs evoked by steps (300 ms) to voltages over the range -70 to +70 mV with an initial holding potential of -70 mV. The Kv7 channel activator, retigabine (Reti, 20 μM) increased K⁺ currents but was inhibited by application of the inhibitor, linopirdine (Lino, 10 μM). B. Group I-V curves show that retigabine increases K⁺ currents while linopirdine after retigabine decreases K⁺ currents in a voltage dependent manner (n = 6 mice, 22 cells). Insert shows a limited voltage range highlighting inward current at negative potentials (for E_Rev values see Table 3). 2 way, repeated measures, ANOVA with Bonferroni multiple comparisons post hoc test ; *P< 0.05 vs. Con, # P<0.05 vs. retigabine. C. Normalized conductance plotted as a function of voltage. Curve fitting was performed using a Boltzmann function; V_1/2 values are shown in Table 3. D. Retigabine-sensitive K⁺ current calculated by subtraction of currents recorded in the absence and presence of retigabine. V_1/2 values for panels C and D are shown in Table 3.