中文摘要：

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~（-6）mol/L、3×10~（-6）mol/L、10~（-5）mol/L、3×10~（-5）mol/L和10~（-4）mol/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~（-4）mol/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~（-5）mol/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~（-3）mol/L）、氯化钡（10~（-4）mol/L）、格列苯脲（10~（-5）mol/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~（-6）mol/L、10~（-5）mol/L和10~（-4）mol/L）可浓度依赖性抑制2.5 mmol/L Ca Cl_2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。

英文摘要：

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 Cl_2（ 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 ＋）.