【摘要】 目的观察氧化苦参碱(oxymatrine,Om)对家兔离体胸主动脉环的收缩作用及其可能机制。方法按主动脉环实验方法,取兔胸主动脉制环,观察Om对累积量效曲线的影响。结果Om对家兔胸主动脉环具有剂量依赖性的收缩效应(10-4-10-1mol/L),酚妥拉明对此无拮抗作用;Om(10-4mol/L)使氯化钾累积量效曲线向左上方移动,维拉帕米(vera-pamil,Ver)可阻断此作用。Om可显著增强高浓度去甲肾上腺素(noradrenalin,NA)收缩血管的作用,Om(10-3mol/L)使氯化钙量效曲线向左上方移,最大效应增大,维拉帕米可阻断此作用。无钙液条件下Om对血管平滑肌不产生收缩作用。结论Om通过电压依赖性钙离子通道促进钙内流而收缩家兔离体胸主动脉环。更多还原

【Abstract】 Objective To explore the effect of oxymatrine（Om） on the rabbit isolated aorta ring. Methods According to the method of isolated aorta ring contraction,the effect of Om on cumulative dose-response curve was observed. Results Om(10^-4-10^-1 mol/L) had a dose-dependent effect on the contraction of the rabbit isolated aorta ring.But phentolamine(10^-4 mol/L) had no this effect.Om(10^-4 mol/L) made the dose-response curve of KCl shift to the left and upward,and Om(10^-3 mol/L) made the dose-response curve of CaCl₂ shift to the left and upward,but verapamil could block the effect.Om could remarkedly enhance the arota contraction induced by NA(5×10^-5-10^-4mol/L),however,it did not affect the contraction elicited by NA(5×10^-9-10⁵ mol/L). Conclusion Om could enhance contraction of the aorta mainly by facilitating Ca²⁺ influx through voltage-sensitive Ca²⁺ channels in the smooth muscle cell membrane.更多还原