槲皮素对大鼠血管平滑肌肌张力的影响

摘要

[目的]观察槲皮素对血管平滑肌肌张力的影响并初步探讨其机制。[方法]Wistar大鼠，取胸主动脉，制成血管环，采用离体血管环灌流法，观察不同浓度的槲皮素对血管平滑肌肌张力的影响。[结果]对于内皮完整的血管环，低浓度(≤10-5mol·L-1)槲皮素可明显抑制去甲肾上腺素或氯化钾引起的血管收缩，且在一定浓度范围内呈剂量依赖性；对于去内皮的血管环，抑制作用则不明显；高浓度(＞10-5mol·L-1)槲皮素，无论是对于内皮完整的还是去内皮的血管环，均可使血管收缩，其收缩作用可被异博定阻断。[结论]槲皮素在低浓度时，对于非内皮损伤所致的高血压具有一定的降压作用；同时槲皮素可激活血管平滑肌L-1型钙通道，因此高浓度则表现出相反作用。%[Objective] To investigate the effects of quercetin on the tension of vascular smooth muscle of rats and its mechanism. [Methods] The isolated aorta ring was prepared,and the effects of quercetin in different concentrations on the tension of vascular smooth muscles were observed. [Results] Quercetin in low concentration(≤10-5mol/L)relaxed intact rat aorta rings in concentration-dependent manner,which had been precontracted with noradrenalin or KCl.but had little effect on those from which the endothelium had been removed;quercetin in high concentration(＞10-5mol/L)contracted rat aorta rings;verapamli counteracted this effect. [Conclusion] Quercetin had double effects on the tension of vessels:in low concentration,it might be antihypertensive for the patient with hypertension whose endothelium was intact,but the concentration must be low because of its active effect on L-type calcium channel.