Research Article

Calycosin and Formononetin Induce Endothelium-Dependent Vasodilation by the Activation of Large-Conductance Ca2+-Activated K+ Channels (BKCa)

Figure 2

Concentration-response curves for calycosin-induced relaxation in the rat mesenteric arteries. (a) Vasorelaxation induced by calycosin with DMSO vehicle, or in the presence and absence of endothelium (; ). (b) Calycosin-induced vasorelaxation in the presence and absence of endothelium, or L-NAME (300 μM) pretreatment in endothelium-intact arteries (; versus endothelium denuded). (c, d) Calycosin-induced vasorelaxation with pretreatments of either TEACl (3 mM; ), glibenclamide (10 μM), apamin (50 nM) plus ChTX (50 nM), or IbTX (200 nM; ). (e) Calycosin-induced vasorelaxation with IbTX (200 nM) pretreatment in endothelium-denuded arteries. (f) Calycosin-induced vasorelaxation with precontractions by methoxamine (10 μM) or KCl (60 mM; ) in endothelium-intact arteries. Data were shown as mean ± SEM. ChTX, charybdotoxin; IbTX, iberiotoxin; TEACl, tetraethylammonium chloride.