论文部分内容阅读
目的：探讨乙酰胆碱（Ａｃｈ）致家兔肺动脉内皮依赖性超极化作用．方法：采用标准微电极技术观察Ａｃｈ对家兔离体肺动脉平滑肌细胞膜电位的作用以及阿托品和高钾对上述作用的影响．结果：内皮完整的肺动脉平滑肌的静息膜电位为－５５．０±３．０ｍＶ．Ａｃｈ（１±１０￣（－７）～１±１０￣（－４）ｍｏｌ／Ｌ）可使上述标本产生浓度依赖性的超极化作用，该作用在去除血管内皮的条件下消失．阿托品（１±１０￣（－５）ｍｏｌ／Ｌ）和高钾（６０ｍｍｏｌ／Ｌ）均可拮抗Ａｃｈ的超极化作用．结论：Ａｃｈ可能通过血管内皮释放的超极化因子使平滑肌细胞的钾通道开放，膜电位超极化．
Objective: To investigate the pulmonary artery endothelium-dependent hyperpolarization induced by acetylcholine (Ach) in rabbits. Methods: The effects of Ach on the membrane potential of isolated pulmonary artery smooth muscle cells of rabbits and the effects of atropine and high potassium on the above effects were observed by standard microelectrode technique. Results: The resting membrane potential of intact pulmonary artery smooth muscle was -55.0 ± 3.0 mV. Ach (1 ± 10 ~ (-7) ~ 1 ± 10 ~ (-4) mol / L) produced a concentration-dependent hyperpolarization, which disappeared with the removal of vascular endothelium. Atropine (1 ± 10 ~ (-5) mol / L) and high potassium (60 mmol / L) could antagonize the hyperpolarization of Ach. CONCLUSION: Ach may open the potassium channels of smooth muscle cells through hyperpolarizing factors released by vascular endothelium, hyperpolarization of membrane potential.