内皮细胞乙酰胆碱靶标不同于M受体的药理学特征

目的 研究内皮细胞乙酰胆碱靶标与M受体药理学特征的差异。方法 采用离体血管环实验方法,观察抗M_3受体的单克隆抗体和M受体激动剂毛果芸香碱对乙酰胆碱引起的内皮依赖性舒张血管作用的影响。结果 毛果芸香碱能够剂量依赖性拮抗乙酰胆碱诱导的内皮依赖性血管舒张作用,其拮抗性质为非竞争性拮抗;抗M_3受体的单克隆抗体不影响乙酰胆碱诱发的内皮依赖性舒张血管作用,但能拮抗乙酰胆碱诱发的离休肠肌收缩作用。结论 内皮细胞乙酰胆碱靶标的药理学特征不同于经典M受体。

Pharmacological characteristics of the endothelial-target for acetylcholine different from muscarinic receptors

AIM To examine whether the endo-thelial-target for acetylcholine is different from muscarinic receptors. METHODS By means of isometrictension test in isolated ring segment of artery derived from rat, we observed the effects of monoantibody against M3 receptors and pilocarpine on endothelium-dependent vascular relaxation induced by acetylcholine. RESULTS The endothelium-dependent vascular relaxation induced by acetylcholine could be blocked by pilocarpine in dose-dependent manner in isolated preparation derived from rat artery. The antagonism of pilocarpine was fit for noncompetitive characteristics; the endothe-lium-dependent vascular relaxation induced by ace-tylcholine could not be blocked by monoantibody a-gainst M3 receptors, but contraction tension induced by acetylcholine in isolated rat ileum could be blocked by monoantibody against M3 receptors. CONCLUTION The endothelial target for acetylcholine had the unique pharmacological characteristics different from those of muscarinic receptor.