哌替啶的舒血管作用及其机制

Mechanisms of pethidine-induced vasodilatation

目的 :探讨哌替啶扩张血管导致低血压的机制。方法 :制备大鼠离体主动脉环 ,记录血管环张力 ,观察哌替啶对高钾和苯肾上腺素 (Ph E)预收缩血管的作用。结果 :哌替啶不影响血管的静止张力 ,但可对高钾和 Ph E诱导的收缩产生非内皮依赖的舒张作用 ,并呈剂量 -反应关系。哌替啶既不影响咖啡因诱导的血管收缩 ,也不改变钌红作用后对高钾诱导收缩的抑制作用。在无钙条件下 ,哌替啶仍能抑制 Ph E的收缩 ,也抑制后续加入钙后引发的收缩。结论 :哌替啶对高钾和 Ph E诱导的血管收缩有舒张作用 ,机制可能与其阻断细胞膜钙通道和抑制 IP3敏感钙池的钙释放有关。

Objective: To investigate the vasodilating effects of pethidine, particularly in association with intracellular calcium. Methods: Aorta rings of Sprague-Dawley rats, with or without endothelium, were prepared in organ bath to measure the vascular tone. Pre-contractions by KCl (80 mmol/L) and phenylephrine (PhE) (10 -6 mol/L) were induced. Results: Pethidine did not alter the resting tension of aorta rings, but produced dose-dependent relaxation in KCl and PhE pre-treated aorta rings with or without endothelium. Pethidine did not change the caffeine-stimulated contraction, and still had similar inhibition in KCl pre-contracted aorta rings after pretreatment with ruthenium red. Pethidine decreased the contractile responses induced by PhE in Ca 2+-free solution or by adding calcium into Ca 2+-free solution. Conclusion: Pethidine could produce an endothelium-independent vasodilatation in KCl and PhE pre-contracted aorta rings, which is related to inhibition of Ca 2+ entry and IP3-sensitive Ca 2+ release in vascular smooth muscle.