【摘要】 目的 :研究滨蒿内酯 (scoparone ,Scop)对离体大鼠主动脉平滑肌张力的影响。方法 :通过测定离体血管环张力变化 ,观察Scop对主动脉平滑肌的舒张作用及与苯肾上腺素 (PE)、普萘洛尔 (Prop)和氯化钾 (KCl)之间的相互作用。结果 :Scop舒张离体主动脉平滑肌 ,并且对内皮完整 (EC +)标本的舒张作用明显大于去内皮 (EC - )标本 ,半抑制浓度 (IC50 )分别为 (10 0± 0 4 ) μmol/L(CE +)与 (83 2± 0 8) μmol/L(EC - ) (P <0 0 1) ;Scop使PE量效曲线下移 ,呈非竞争性抑制 ,亲和力指数 (PD2 )分别为 4 93± 0 0 5 (EC +)与 2 94± 0 14 (EC - ) ;Prop(1μmol/L)对Scop舒张血管平滑肌作用无影响 ;Scop不能抑制Prop所致血管平滑肌收缩 ;Scop对血管平滑肌的依内钙及依外钙性收缩均有明显抑制作用。结论 :Scop可舒张离体大鼠主动脉平滑肌 ,此作用与内皮细胞的功能有一定关系。Scop抑制血管平滑肌依内钙与依外钙性收缩可能是Scop舒张血管平滑肌的主要机制更多还原

【Abstract】 﨩bjective: [WT5"BZ] This study was designed to investi ga te the possible mechanisms of the vascular dilatory effect of scoparone(Scop). [WT5"HZ]Methods: [WT5"BZ] Rings of rat thoracic aorta were studied in organ baths. We observed the vasodilator effect of Scop and its interactions with phen ylephrine(PE), propranolol(Prop), and potassium chloride(KCl). [WT5"HZ]Results: [WT5"BZ] Scop relaxed the isolated rat aortic smooth muscles precontracte d by 10 -6 mol/L PE,and IC 50 values were(10.0±0.4)μmol/L(EC+) and (83.2±0.8)μmol/L(EC-), respectively (P<0.01). Scop depressed the dose response cureves to PE in a dose dependent manner, with PD 2 value of 4.93 ±0.05(EC+) and 2.94±0.14(EC-), respectively. Vasodilator effect of Scop was no t affected by Prop(1 μmol/L). Scop did not depress the contractile responses to 60 mmol/L potassium chloride. Scop significantly inhibited the phasic and tonic contraction induced by PE(10 -6 mol/L) (P< 0.01 ). [WT5"HZ]Conclus ion: [WT5"BZ]Scop relaxed aortic smooth muscles, and the presence of endothel ium facilitated this vascular dilatory effect. Scop inhibited both the phasic an d tonic contraction, which may be the key mechanism of the vasodilator effect of Scop. [WT5"HZ]更多还原