Calycosin and Formononetin Induce Endothelium-Dependent Vasodilation by the Activation of Large-Conductance Ca2+-Activated K+ Channels (BKCa)
Concentration–response curves for formononetin-induced relaxation in the rat mesenteric arteries. (a) Formononetin-induced vasorelaxation with DMSO vehicle, or in the presence and absence of endothelium (; ). (b) Formononetin-induced vasorelaxation in the presence and absence of endothelium, or L-NAME (300 μM) preincubation in endothelium-intact arteries (; versus endothelium denuded). (c, d) Formononetin-induced vasorelaxation with pretreatments of either TEACl (3 mM; ), glibenclamide (10 μM; ), apamin (50 nM) plus ChTX (50 nM; ), or IbTX (200 nM; ). (e) Formononetin-induced vasorelaxation with IbTX (200 nM) preincubation in endothelium-denuded arteries. (f) Formononetin-induced vasorelaxation with precontractions of methoxamine (10 μM) or KCl in endothelium-intact arteries (60 mM; ). Data were shown as mean ± SEM. ChTX, charybdotoxin; IbTX, iberiotoxin; TEACl, tetraethylammonium chloride.