Figure 5From: Potassium channel openers and prostacyclin play a crucial role in mediating the vasorelaxant activity of Gynura procumbens Effect of F1 on CaCl 2 -induced contraction in Ca 2+ - and K + -free solution containing PE. Concentration-response curves for CaCl2 were determined in aortic rings in the absence and presence of F1 (2 or 4 mg/ml). Values are mean ± S.E.M. (n = 6). **P < 0.01 compared with control (without F1).Back to article page