氨氯吡咪对预收缩大鼠胸主动脉血管环的作用及其机制探讨  

Effect and Mechanism of Amiloride on Rat Isolated Aortic Rings of Precontracted

作　　者：陈媛[1] 任俊杰[2] 武冬梅[2] 梁月琴[2] 王君[2] 

机构地区：[1]山西医科大学药理学教研室 [2]山西医科大学

出　　处：《中西医结合心脑血管病杂志》2009年第12期1443-1446,共4页Chinese Journal of Integrative Medicine on Cardio-Cerebrovascular Disease

基　　金：山西省自然科学基金项目(No.2008011076-4);山西省回国留学人员科研基金资助项目(No.2007-427)

摘　　要：目的观察氨氯吡咪(AM)对预收缩大鼠胸主动脉血管环的舒张作用并探讨其可能机制。方法采用离体血管环灌流方法,在用KCl(6×10-2mol/L)或去甲肾上腺素(NE,1×10-6mol/L)预收缩的去内皮或内皮完整的离体大鼠主动脉环上加入AM,观察其对大鼠主动脉血管环的作用及加入不同工具药后对其舒张血管的影响。结果AM(1×10-6mol/L～3×10-5mol/L)对基础状态的大鼠胸主动脉血管环无作用;对KCl(6×10-2mol/L)和NE(1×10-6mol/L)预收缩的内皮完整或去内皮的胸主动脉血管环有浓度依赖性的舒张作用,对内皮完整血管环的舒张作用强于去内皮的血管环。一氧化氮合酶抑制剂L-NAME及部分钾离子通道阻断剂四乙胺(TEA,1×10-2mol/L)、氯化钡(BaCl2,1×10-3mol/L)预处理对AM诱导的动脉环舒张作用具有明显的抑制效应。结论AM的血管舒张作用具有内皮依赖性,其与内皮NO的合成有关;同时AM可能涉及血管平滑肌细胞的钙激活钾通道和内向整流钾通道的激活。Objective To investigate the effect of amiloride on the rat isolated aorta ring pre - contracted by norepinephrine（NE） or potassium chloride（KCl）. Methods Rings of the isolated rat thoracic aorta were mounted in organ baths and isometric contractile force was measured. Results Amiloride （3 ×10^-6 mol/L to 1 ×10^-4 mol/L） had no effect on the rat isolated aortic rings without stimulated, but in NE（ 1 ×10^-6 mol/L）- preeontracted or KCl（6 ×10^- 2 mol/L）- precontraeted rings, amiloride concentration - dependently reduced the contraction of endothelium - intact or endothelium - denuded aortic rings and reduced the contraction of the former more significant than the latter. The contraction could be prevented by pretreatment with the K^＋ channel inhibitors tetraethylammoniurn（TEA）, BaCl2, and can also be prevented by pretreatment with L - NAME. Conclusion Amiloride could produce remarkable vasodilatation on NE or KCI pre - contracted aorta rings in adult rats,while it didn＇t affect the resting tone. It relaxed via part endothelium - dependent mechanisms. The two different kinds of K^＋ channel seems to play an important role in amiloride - induced decrease of the NE - induced increase in[Ca^2＋] in isolated aorta. Another mechanism was by inhibiting the synthesis of nitric oxide（NO）in the endothelial cell.

关 键 词：氨氯吡咪 胸主动脉环 血管舒张 内皮 血管平滑肌 钾通道 

分 类 号：R965[医药卫生—药理学]