越橘乙醇提取物诱导血管舒张的实验研究

目的探讨越橘乙醇提取物对血管内皮的舒张作用及其机制。方法以大鼠胸主动脉为标本，观察越橘提取物对去氧肾上腺素（PE）预收缩血管的舒张作用及其在血管内皮、平滑肌细胞中作用的机制。结果越橘提取物对由去氧肾上腺素（1．0×10^-5mol／L）引发的血管收缩具有浓度依赖性的松弛作用（P〈0．01），去除血管内皮后舒张作用明显被抑制（P〈0．01）；在内皮完整的血管条中，舒张作用明显被一氧化氮合酶抑制剂L-N-硝基精氨酸甲酯（L—NAME）、亚甲蓝和鸟苷酸环化酶抑制剂（ODQ）所抑制（P〈0．01），血管的舒张作用因维拉帕米浓度的增加而减弱，并且不受吲哚美辛、格列苯脲、四乙基铵、阿托品和普萘洛尔等药物的影响（P〈0．01）。结论越橘提取物具有明显舒张离体血管的作用，其松弛血管的作用是通过内皮依赖的一氧化氮-环鸟苷酸信号转导系统信号途径，还有可能涉及到L-Ca^2＋通道。

The experimental study of vascular relaxation induced by the ethanol extract of Blueberry(BE)

Objective To study the effects and the mechanism of the ethanol extract of Blueberry(BE) on relaxation vascular endothelium or smooth muscle.Methods To use rat aorta as the specimen,to observe the effects of BE on induced relaxation of the phenylephrine-precontracted aorta.and approach the mechanism on vascular endothelium or smooth muscle.Results BE induced relaxation of the phenylephrine-precontracted(1.0×10~(-5)mol·L~(-1) aorta in a dose-dependent way(P<0.01),which was disappeared by removal of functional endothelium(P<0.01).Pretreatment of the aortic tissues with NG-nitro-L-arginine methyl ester(L-NAME),methylene blue,or 1H1,2,4]-oxadiazole-4,3_a]-quinoxalin-1-one (ODQ) inhibited the vascular relaxation induced by BE(P<0.01).BE-induced vascular relaxations were also markedly attenuated by addition of verapamil or diltiazem,while the relaxant effect of BE was not blocked by pretreatment with indomethacine,glibenclamide,tetraethylammonium(TEA),atropine,propranolol(P<0.01).Conclusion These results suggest that BE dilates vascular smooth muscle via endothelium-dependent nitricoxide-cGMP signaling pathway,possible involvement of L-type Ca~(2+) channel.