白杨素对去氧肾上腺素预收缩大鼠主动脉的舒张作用及机制

Vasodilatory effect of Chrysin on phenylephrine-preconstricted rats' aorta and its mechanism study

目的:研究白杨素(Chrysin)对去氧肾上腺素(PE)预收缩大鼠离体主动脉血管环张力的影响及其机制。方法:采用离体血管环张力检测系统,观察Chrysin对PE预收缩血管的舒张作用,通过孵浴一氧化氮合酶抑制剂L-NAME、鸟苷酸环化酶抑制剂MB、环氧合酶抑制剂Indo、钾通道抑制剂4-AP、Ba Cl2、Gli、TEA探讨白杨素对血管张力影响的机制。结果:Chrysin对PE预收缩的血管环具有浓度依赖性的舒张作用,但对去内皮的血管环舒张作用弱于内皮完整的血管环(P<0.05),EC50分别为4.76×10-6mol/L(内皮完整)和1.12×10-5mol/L(去内皮)。L-NAME(10-4mol/L)和MB(10-5mol/L)能部分抑制Chrysin的舒张血管作用(P<0.05),但Indo(10-5mol/L)则无明显作用(P>0.05)。4-AP(10-3mol/L)、Ba Cl2(10-4mol/L)、Gli(10-5mol/L)、TEA(10-3mol/L)预孵后,Chrysin的最大舒张血管作用(Emax)均被部分抑制(P<0.05)。结论:Chrysin可以浓度依赖性地舒张大鼠主动脉,其机制可能与内皮NOS-NO-s GC通路和开放血管平滑肌上钾通道有关,而与前列环素无关。

AIM： To investigate the vasodilatory effect of Chrysin on phenylephrine-preconstricted rats ’ aorta and its possible mechanism. METHODS： In vitro aortic ring perfusion devices was used to observe effects of Chrysin on isolated aortic ring contraction of phenylephrine（ PE） induced rats’ aorta. Effects of Chrysin on blood vessels reaction induced by various inhibitors, including L-NAME,MB,Indo,4-AP,Ba Cl2,Gli and TEA were recorded. RESULTS： Chrysin showed stronger vasodilatory effect on aortic ring of rat in intact endothelium group than that in non-intact group（ P 〈 0. 05）. In intact group,the value of EC50 was 4. 76 × 10-6mol /L for Chrysin. In non-intact group,it was 1. 12 ×10-5mol / L. Treatment of arterial rings with e NOS inhibitor L-NAME and s GC inhibitor MB,but without indomethecin obviously affected the relaxant effects of Chrysin（ P 〈 0. 05）. 4-AP（ 10-3mol / L）,Ba Cl2（ 10-4mol / L）,Gli（ 10-5mol / L）,and TEA（ 10-3mol / L） weakened Chrysin-induced diastolic effect significantly（ P 〈 0. 05）. CONCLUSION：Chrysin exerts vasodilatory effect on rat isolated aorta rings in a concentration-dependent manner. The mechanism might be involved with the activation of NOS,GC of endothelium and K＋channels of vascular smooth muscle.