Fig. 8: The gentisic acid SAR for Kv7.2/3 channel opening.

a Structures of compounds in the GA SAR. b Mean traces recorded from oocytes expressing Kv7.2/3 in the absence (Control; black) or presence of GA analogs (100 µM) (red) using the voltage protocol from Fig. 5a. Scale bars lower left for each pair of traces; n = 5 (2,3-Dihydroxybenzoic acid, 4-Hydroxybenzoic acid, salicyclic acid, 3-Hydroxyphenylacetic acid) or 8 (arbutin, aspirin, benzoic acid, hydroquinone) per group. c Mean peak normalized tail current (G/Gmax) for traces as in (b); n values as in (b), in the absence (black) or presence (red) of compounds indicated (100 µM). d Mean unclamped oocyte membrane potential for oocytes as in (b); n values as in (b). e Mean traces recorded from oocytes expressing Kv7.2/3 in the absence (Control; black) or presence of GA analogs (100 µM) (red) using the voltage protocol from Fig. 5a. Scale bars lower left for each pair of traces; n = 5 (3-Hydroxyphenylboronic acid, calcium dobesilate, 2,5-Dihydroxybenzoaldehyde) or 8 (2,5-Dihydroxybenzonitrile) per group. f Mean peak normalized tail current (G/Gmax) for traces as in (e); n values as in (e), in the absence (black) or presence (red) of compounds indicated (100 µM). g Mean unclamped oocyte membrane potential for oocytes as in (e); n values as in (e). h Mean Kv7.2/3 ΔV_0.5act for the compounds tested in panels (b–g) (n values as in b and e). ****P < 0.0001 (green) GA vs all other compounds except calcium dobesilate; ****P < 0.0001 (magenta) calcium dobesilate vs all other compounds except GA; GA vs calcium dobesilate: P > 0.05. GA data analyzed from traces as in Fig. 3a (n = 10). Error bars indicate SEM. n indicates number of biologically independent oocytes. Statistical comparisons by t-test except panel (h), which was by ANOVA with multiple comparisons. Dashed lines indicate zero current level.