羟基积雪草苷舒血管作用的选择性作用特点研究

Study of the selective characteristics of the vasorelaxation of madecassoside

目的:探讨羟基积雪草苷(madecassoside,MC)对血管平滑肌的选择性作用特点。方法:分离大鼠胸主动脉和尾动脉以及回肠和膀胱平滑肌条,采用张力换能器及生物信号采集处理系统测定平滑肌张力变化;应用小肠推进实验考察对小肠蠕动的影响。结果:MC对去甲肾上腺素(NE)引起的胸主动脉和尾动脉收缩均有抑制作用,但对尾动脉作用更明显;同法,MC对高血压大鼠胸主动脉的作用明显比正常大鼠胸主动脉强;其它部位平滑肌中:无论是自发性收缩还是有激动剂存在的条件下,各剂量MC对离体回肠及膀胱平滑肌的收缩均无明显影响;在小肠推进实验中,MC对小肠推进率无显著作用。结论:MC具有舒张血管活性,且对血管平滑肌具有较好的选择性;对周围小动脉的作用明显强于中央动脉;对高血压大鼠动脉的舒张作用比正常大鼠更明显。

Objective： To investigate the selective characteristics of the vasorelaxation of madecassoside （MC）. Methods： Thoracic aortic rings, tail arterial rings and the smooth muscle of ileum and bladder were isolated from rats and tension sensors were used for determining contractile tension in vitro. In addition, to determine the effects on the small intestine propulsive function in vivo. Results： MC relaxed thoracic aortic rings and tail arterial rings in a concentration-dependent manner after precontraction induced by NE. However, the relaxation effects on tail arterial rings were more significant than that on thoracic aortic rings. By the similar method, the relaxation effects on thoracic aortic rings of hypertensive rats were more significant than that of normal rats ; In other kinds of smooth muscle models ： No significant effect of MC on spontaneous contraction and ACh-induced contraction of the smooth muscle isolated from ileum was observed ; Reference drug Atropine sulfate inhibited propelling rate of the small intestine in mice significantly, however no significant effect of MC on its was observed ; MC did not have a significant effect on extent of contraction and maximal response of the smooth muscle isolated from bladder isolated of rats. Conclusions： The results demonstrated that MC could relax vascular smooth muscle selectively; The effect of the vasorelaxation was stronger on the peripheral arteriole than that on the central aorta; Moreover, MC showed the stronger vasodilator effect on artery of hypertensive rats compared with that of normal rats.