Figure 1From: Polygonum viviparum L. induces vasorelaxation in the rat thoracic aorta via activation of nitric oxide synthase in endothelial cells Relaxation effect of Polygonum viviparum L. (PV) in isolated rat thoracic aorta. The aorta was removed from a rat, and fat and tissue were carefully dissected away in normal 37°C Krebs solution. Phenylephrine (PE) at 3 μM induced a transient phasic contraction followed by tonic contraction, which lasted at least 10 min in intact or endothelial-denuded aorta. Acetylcholine (ACh) at 10 μM induced relaxation in intact (A, upper trace) but not denuded (A, lower trace) aorta. PV at 100 μg/ml relaxed PE-precontracted intact (B, upper trace) but not denuded (B, lower trace) aorta. (C) Concentration-response curve of vasorelaxation caused by PV on PE-precontracted rat intact aorta. Data are expressed as the mean ± standard error of the mean (S.E.M.) (n ≥ 5 animals per time point).Back to article page