天钩降压胶囊对家兔主动脉血管条收缩反应的影响

目的:观察天钩降压胶囊对家兔主动脉条收缩反应的影响,探讨其降压作用机制.方法:将家兔离体主动脉条置于灌流肌槽中,记录天钩降压胶囊提取物对去甲肾上腺素(NE)、氯化钾(KCl)、氯化钙(CaCl2)诱导的主动脉条收缩作用的影响,以及对NE诱导的主动脉条细胞内钙及细胞外钙依赖性收缩反应的影响.结果:天钩降压胶囊1,3,5g·L-1剂量组均能使NE,CaCl2引起的主动脉条最大收缩反应降低(P＜0.01);对NE诱发主动脉条细胞内钙及细胞外钙依赖性收缩均有明显抑制(P＜0.01),对细胞外钙依赖性收缩的抑制作用更显著;对KCl引起的动脉条收缩反应无明显影响.结论:天钩降压胶囊可通过影响细胞内钙离子浓度促进血管平滑肌舒张从而发挥降压作用.其机制可能主要通过影响受体操纵的Ca2+通道(ROC),对电压依赖性Ca2+通道(PDC)作用不显著.对NE诱发主动脉条细胞外钙依赖性收缩的抑制作用优于对细胞内钙依赖性收缩的作用.

Effect of Tiangou Jiangya capsule on rabbit aortic strip contraction

Objective: To observe the effect of Tiangou Jiangya capsule on isolated rabbit aortic strips, and to discuss its anti-hypertensive mechanism. Method: The isolated rabbit aortic strips were placed in perfusion baths, and induced to contract by norepinephrine(NE), KCl and CaCl₂ respectively, then Tiangou Jiangya capsule extraction was added to observe its effect on the contraction. The effect on intracellular Ca²⁺ dependent contraction and extracellular Ca²⁺ dependent contraction induced by NE were also studied. Result: The Tiangou Jiangya capsule(1,3,5 g·L^-1) can reduce the largest contract reaction of aortic strips induced by NE or CaCl₂ (P<0.01). It can reduce both intracellular Ca²⁺ dependent contraction and extracellular Ca²⁺ dependent contraction induced by NE (P<0.01), and the effect on extracellular Ca²⁺ dependent contraction is more significant. But the Tiangou Jiangya capsule has no significant effect on KCl induced contraction. Conclusion: Tiangou Jiangya capsule can regulate intracellular Ca²⁺ concentration and help to relax the vascular smooth muscle. The mechanism could be regulating the receptor-operated Ca²⁺ channel. The effect on extracellular Ca²⁺ dependent contraction is more obvious than on intracellular Ca²⁺ dependent contraction induced by NE.