背景:附子为毛莨科乌头子根的加工品,具有温肾回阳,回阳救逆和温里散寒之功效。研究发现其具有明显的强心、降压、扩张血管、镇痛、抗炎及毒性等作用。目的:观察附子水煎剂对主动脉环的舒张作用及机制。方法:采用家兔离体主动脉平滑肌标本,以去甲肾上腺素(10-6 mol/L)预收缩主动脉后给予0.5,1.0,2.0,4.0,8.0 g/L附子水煎剂观察其张力变化。然后将不同浓度的附子水煎剂干预的家兔离体主动脉平滑肌加入去除血管内皮、给予一氧化氮合酶抑制剂左旋硝基精氨酸(1×10-4mol/L)、甲烯蓝(1×10-5 mol/L)、环氧酶抑制剂吲哚美辛(1×10-5 mol/L)和β肾上腺素能受体阻断剂普萘洛尔(1×10-5 mol/L),探讨它们对血管张力变化的影响。结果与结论:附子水煎剂对血管环静息张力无明显影响,但不同剂量的附子水煎剂可使10-6 mol/L去甲肾上腺素预收缩血管产生明显舒张。去除血管内皮、给予左旋硝基精氨酸或给予甲烯蓝可减弱附子水煎剂对血管的舒张作用,但吲哚美辛和普萘洛尔对此无影响。另外,4 g/L附子水煎剂对无内皮细胞血管环去甲肾上腺素和KCl的量效收缩反应无明显影响。提示附子对主动脉的舒张作用是内皮依赖性,与内皮细胞释放的一氧化氮有关,而与平滑肌细胞膜上的受体依赖性Ca2+通道和电压依赖性Ca2+无关。
BACKGROUND:Aconitum carmichaeli Debx (ACD) is the tuberous root of Aconium carmicgaekum, used as cardiotonic to restore yang for the treatment of colapse and shock, to warm the kidney and reinforceyang, and to expel cold and promote the flow ofyang-qi. Studies have found that ACD has obviously cardiotonic, antihypertensive, vasodilatory, analgesic, anti-inflammatory and toxic effects. OBJESTIVE: To observe the vasodilatory effects of a water decoction of ACD on rabbit’s aorta rings and its mechanism. METHODS:Rabbits aorta arteries were isolated, pre-contracted with noradrenaline (10-6 mol/L) and their responses to different concentrations of ACD (0.5, 1.0, 2.0, 4.0, 8.0 g/L) were investigated. The effects of removal of vascular endothelium and different signaling pathway inhibitors (Nω-nitro-L-arginine: 1×10-4 mol/L, methylene blue: 1×10-5 mol/L, indomethacin: 1×10-5 mol/L, propranolol: 1×10-5 mol/L) on ACD-induced vasodilation were also assessed. RESULTS AND CONCLUSION:ACD could not change the resting tension of rabbit aortic rings, but ACD treatment resulted in an obvious relaxation in narodrenaline-precontracted aortic rings and the relaxant effect was dose-dependent. The vasodilatory effect of ACD was significantly reduced by removal of endothelium, 1×10-4 mol/L Nω-nitro-L-arginine and 1×10-5 mol/L methylene blue but not reduced by indomethacin and propranolol. In addition, 4 g/L water decoction of ACD did not decrease the dose-response curves of artery rings to narodrenaline or KCl in the absence of endothelial cels. ACD can relax isolated rabbit’s aorta, which may be related to endothelium-released nitric oxide, but has no significant relevance with receptor-operated and voltage-dependent calcium channels.