骆驼蓬碱对豚鼠回肠平滑肌中钠离子运动的影响。

The influence of harmaline on the movements of sodium ions in smooth muscle of the guinea pig ileum.

作者信息

Suleiman M S, Hider R C

出版信息

Mol Cell Biochem. 1985 Jul;67(2):145-50. doi: 10.1007/BF02370173.

Abstract

The effect of changing the extracellular concentration of both Na+ and K+ on the longitudinal muscle of the guinea-pig ileum was studied in the presence and absence of harmaline. A decrease in extracellular Na+ concentration was found to produce a dose-dependent contractile response, which may suggest the existence of a Na-Ca exchange mechanism in this muscle. Harmaline (2 X 10(-4) M) was found to reversibly inhibit this contraction and was also found to selectively block the tonic component of high-K induced contradictions. In view of the fact that harmaline is a non-competitive inhibitor of Ca-induced contractions (Hider et al., Europ. J. Pharmacol., 71, 87, 1981), the action of harmaline was interpreted as being a specific inhibitor of the Na-Ca exchange mechanism, binding specifically to Na+ coordination sites.

摘要

在有和没有哈尔满碱的情况下，研究了改变细胞外Na⁺和K⁺浓度对豚鼠回肠纵肌的影响。发现细胞外Na⁺浓度降低会产生剂量依赖性收缩反应，这可能表明该肌肉中存在钠-钙交换机制。发现哈尔满碱（2×10⁻⁴M）可可逆地抑制这种收缩，还发现它能选择性地阻断高钾诱导的收缩的强直成分。鉴于哈尔满碱是钙诱导收缩的非竞争性抑制剂（希德等人，《欧洲药理学杂志》，71卷，87页，1981年），哈尔满碱的作用被解释为是钠-钙交换机制的特异性抑制剂，它特异性地结合到Na⁺配位位点上。