槲皮素对大鼠血管平滑肌肌张力的影响

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-型钙通道,因此高浓度则表现出相反作用。

Effects of Quercetin on the Tension of Vascular Smooth Muscle of Rats

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(-5)mol/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(-5)mol/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.