杭白菊乙酸乙酯提取物的舒血管作用及相关机制

Vasorelaxant effect and underlying mechanism of EtOAc extract from Chrysanthemum morifolium in rat thoracic aorta

目的 :研究杭白菊乙酸乙酯提取物 (CME)的舒血管作用及机制。方法 :大鼠胸主动脉环张力测定法。结果 :CME可以浓度依赖性地降低主动脉环由苯肾上腺素 (PE)及高钾预收缩的血管张力 ,其对内皮完整血管的作用显著大于去内皮血管 (P <0. 0 5 )。L -N -硝基精氨酸甲酯 (L -NAME)、亚甲蓝可以显著降低CME的舒血管作用 (P <0 .0 1) ;将主动脉与CME共孵育后 ,血管NOS活力呈现浓度依赖地增高 (P <0 . 0 1) ;吲哚美辛对CME的作用无显著影响 ;SKF - 5 2 5A与L -NAME合用 ,与单用L -NAME无显著差异。CME的舒血管作用不受普萘洛尔、四乙氨、氯化钡、4 -氨基吡啶、5 -羟基癸酸的影响 ;但却可被格列苯脲显著削弱 (P <0 . 0 1)。无钙环境下CME对PE引起的收缩无显著影响 ;无钾环境下以及无钙环境下渐加钙 ,CME对PE引起的收缩有显著影响 (P <0 .0 5 )。结论 :CME具有显著的舒血管作用 ,其机制既与NO介导的途径有关 ,也与抑制电压依从性钙通道和受体操纵性钙通道以及激活ATP敏感钾通道有关。

AIM: To investigate the vasorelaxant effect and mechanism of EtOAc extract from Chrysanthemum morifolium Ramat (CME). METHODS: The effects of CME on the contraction of rat thoracic a orta were examined. RESULTS: CME caused concentration-dependent relaxation of aorta rings precontricted with phenylephrine and K+. The effect in endothelium-intac t aorta was more effective than that in endothelium-deduced aorta. NG-nitro-L- arginine methylester, methylene blue and glibenclamide attenuated the effect of C ME significantly. However, indomethacin, propranolol, tetraethylammonium, BaCl 2, 4-aminopyridine and 5-hydroxydecanoate did not affect CME effect. The effect of SKF-525A combined with L-NAME had no obvious difference with that of L-NAME o n CME-induced relaxation. NOS activity in aorta was increased markedly by CME in vitro. CME did not reduced the contraction elicited by PE in Ca 2+-f ree medium, but reduced the contraction induced by PE in K+-free solution or C a 2+ free following input Ca 2+. CONCLUSION: CME induces both endothelium-dependent and independe nt relaxation. NO and cGMP are likely involved in the endothelium-dependent rela xation, inhibition of voltage-dependent or receptor-operate Ca 2+ channel a nd activation of ATP-sensitive K+ channel contribute in part to the endotheliu m-independent relaxation by CME.