在等渗和高渗溶液中，对由高浓度钾收缩的平滑肌制剂，匹那地尔产生的不同舒张反应。

Differential relaxant responses to pinacidil of smooth muscle preparations contracted by a high concentration of potassium in isoosmolar and hyperosmolar solutions.

作者信息

Nielsen-Kudsk J E, Mellemkjaer S, Nielsen C B, Siggaard C

机构信息

Institute of Pharmacology, University of Aarhus, Denmark.

出版信息

Pharmacol Toxicol. 1990 Sep;67(3):252-4. doi: 10.1111/j.1600-0773.1990.tb00823.x.

DOI:10.1111/j.1600-0773.1990.tb00823.x

PMID:2255682

Abstract

Contractions were produced in guinea-pig trachealis, aorta and pulmonary artery by depolarization with 124 mM K+ using two commonly applied techniques. Addition of KCl to the organ bath solution making it hyperosmolar induced slowly developing contractions, which were only weakly inhibited by pinacidil. Hyperosmolar mannitol-induced contractions showed similar characteristics. In contrast, contractions elicited by isoosmolar K+ Krebs solution developed more rapidly and could be completely suppressed by pinacidil (10(-6)-10(-3) M) in a concentration-dependent manner. The findings explain previously published discrepant results on the relaxant response to pinacidil of smooth muscle preparations contracted by high concentrations of K+, and indicate other mechanisms of action for pinacidil in addition to K+ channel opening, in the concentration range 10(-6)-10(-3) M.

摘要

采用两种常用技术，用124 mM K⁺使豚鼠气管、主动脉和肺动脉去极化，从而引发收缩。向器官浴溶液中添加KCl使其变为高渗，会引发缓慢出现的收缩，而吡那地尔对其仅有微弱的抑制作用。高渗甘露醇引发的收缩表现出相似的特征。相比之下，等渗K⁺ Krebs溶液引发的收缩发展更快，并且吡那地尔（10⁻⁶ - 10⁻³ M）能以浓度依赖的方式完全抑制这种收缩。这些发现解释了之前发表的关于高浓度K⁺收缩的平滑肌制剂对吡那地尔松弛反应的相互矛盾的结果，并表明在10⁻⁶ - 10⁻³ M浓度范围内，除了开放K⁺通道外，吡那地尔还有其他作用机制。