Figure 6From: Potassium channel openers and prostacyclin play a crucial role in mediating the vasorelaxant activity of Gynura procumbens Effect of F1 on NA- and caffeine-induced contraction in Ca 2+ -free solution. Aortic rings were preincubated with vehicle (control) or BU (2 or 4 mg/ml) and NA (10-6 M) or caffeine (45 mM) was added to trigger the contractions. Values are mean ± S.E.M. (n = 6).Back to article page