【摘要】 目的:研究白杨素（chrysin）对离体大鼠主动脉肌源性反应的影响,并探讨其作用机制。方法:分离SD大鼠主动脉,采用离体血管环灌流装置观察chrysin对血管环的基础张力及对60 mmol/L KCl预收缩血管的舒张作用,并结合不同抑制剂处理,探讨其作用于血管环的可能机制。结果:Chrysin(10^-6mol/L、3×10^-6mol/L、10^-5mol/L、3×10^-5mol/L和10^-4mol/L)对基础状态血管无明显影响,但对60 mmol/L KCl预收缩的血管环具有浓度依赖性舒张作用,并且去内皮组舒张作用弱于内皮完整组（P<0.05）。NOS抑制剂L-NAME(10^-4mol/L)处理血管后,chrysin的舒张血管作用部分被抑制（P<0.05）,COX抑制剂吲哚美辛(10^-5mol/L)处理血管后无明显抑制作用。钾通道阻滞剂4-氨基吡啶(10^-3mol/L)、氯化钡(10^-4mol/L)、格列苯脲(10^-5mol/L)和四乙胺(10^-3mol/L)预孵后,chrysin舒张血管作用均被部分抑制（P<0.05）。Chrysin(10^-6mol/L、10^-5mol/L和10^-4mol/L)可浓度依赖性抑制2.5 mmol/L Ca Cl₂引起的主动脉收缩。结论:Chrysin能够浓度依赖性舒张大鼠主动脉,其作用机制可能与促进一氧化氮释放、激活4种K⁺通道及减少细胞内钙离子浓度有关。更多还原

【Abstract】 AIM: To determine the effect of chrysin on the relaxation of isolated rat aortic rings and its mechanisms. METHODS: On ex vivo aortic ring perfusion device,the influence of chrysin on isolated aortic ring at basic condition or contraction of the aorta induced by KCl（ 60 mmol / L） was observed,and the effects of chrysin on the blood vessel reaction induced by various drugs were recorded. RESULTS: Chrysin( 10^{- 6}mol / L,3 × 10^{- 6}mol / L,10^{- 5}mol / L,3 ×10^{- 5}mol / L and 10^{- 4}mol / L) had no effect on isolated aortic ring at basic condition. Chrysin had stronger vasodilatation effect in intact group than that in non-intact group（ P < 0. 05）. Treatment of the arterial rings with e NOS inhibitor LNAME,but not with indomethecin or endothelium denudation,obviously affected the relaxant effects of chrysin（ P <0. 05）. When the contractions were induced by KCl,4-aminopyridine( 10^{- 3}mol / L),Ba Cl₂( 10^{- 4}mol / L),glibenclamide( 10^{- 5}mol / L),and tetraethylammonium( 10^{- 3}mol / L) weakened chrysin-induced diastolic effect（ P < 0. 05）. Chrysin significantly inhibited contracting effect of KCl on aorta rings in 2. 5 mmol / L Ca^{2 +}medium（ P < 0. 05）. CONCLUSION:Chrysin exerts vasodilating effect on rat isolated aorta rings in a dose-dependent manner. The mechanism might be related to promoting NO release,activating K⁺channels and decreasing the concentration of cytoplasmic Ca^{2 +}.更多还原