心脉隆对离体人脐动脉血管张力的影响及其机制

目的：探讨心脉隆对离体人脐动脉血管张力的影响，并分析其机制。方法：运用离体血管张力测定实验方法，累积加入不同浓度的心脉隆，观察其对静息人脐动脉的张力影响；加入60 mmol·L^-1 KCl、1 μmol·L^-1苯肾上腺素（PE）使血管收缩、张力平稳后，观察不同浓度心脉隆对预收缩的人脐动脉张力的影响；同时观察细胞外Ca²⁺浓度、L-型钙通道阻滞剂维拉帕米（VEP）对心脉隆血管效应的影响。结果：心脉隆能浓度依赖性收缩静息状态下内皮完整的离体人脐动脉，对KCl、PE预收缩的离体人脐动脉有进一步增加张力的作用，在无钙灌流液中诱发的血管收缩效应明显减弱，随着细胞外Ca²⁺浓度增加其致血管收缩张力增加，维拉帕米能显著抑制心脉隆对人脐动脉的收缩反应。结论：心脉隆可促进细胞外Ca²⁺内流和细胞内Ca²⁺释放，从而具有浓度依赖性地收缩离体人脐动脉的作用。

Effect and mechanism of Xinmailong on constrictions of human umbilical artery ex vivo

OBJECTIVE To investigate the effect of Xinmailong on vascular tension of isolated human umbilical artery and analyze its mechanism. METHODS The effects of different concentrations of Xinmailong on the tension of resting human umbilical artery were observed by measuring the vascular tension in vitro. The effects of different concentrations of Xinmailong on the tension of precontracted human umbilical artery were observed after the vascular contraction and the tension were stabilized by adding 600 mmol·L^-1 KCl and 1 μmol·L^-1 phenylephrine (PE).RESULTS The isolated human umbilical artery with intact endothelium under resting state was contracted in a concentration-dependent manner. The isolated human umbilical artery pre-contracted with KCl and PE was further increased in tension The vasoconstrictor effect evoked in calcium-free perfusate was significantly attenuated, and verapamil could significantly inhibit the contractile response of cardiac meridians to human umbilical artery as the extracellular Ca²⁺ concentration increased to increase its vasoconstrictor tension. CONCLUSION Xinmailong can promote the influx of extracellular Ca²⁺ and release of intracellular Ca²⁺, and thus can contract isolated human umbilical artery in a concentration-dependent manner.