The aims of the present study are to investigate the effect of vasoconstriction and to explore the mechanism of rutae- carpine. The research findings showed that rutaecarpine could induce contractions of the rat thoracic aorta in vitro. The inhibitors of Rho-kinase and inositol 1,4,5-triphosphate receptor （IP 3 R） could suppress the effect of rutaecarpine-induced vasoconstriction. In the study of A7r5 cells （a line of smooth muscle cells）, 300 μg/L rutaecarpine promoted the concentration of intracellular Ca 2＋ and enhanced the IP 3 R expression, which connects with 1,4,5-triphosphate to evoke the release of Ca 2＋ from the intracellular stores. Rutaecarpine increased the RhoA mRNA expression when the cells were pretreated with inhibitor H-1152, and improved the levels of phosphorylation of myosin light chain phosphatase （MLCP） and myosin light chain （MLC）. These results suggest that rutaecarpine plays a role in vasoconstriction relative to the RhoA/MLCP-MLC signaling pathway, which denotes a new field of rutaecarpine in pharmacology.
目的:子宫平滑肌内存在多种5-HT受体,5-HT通过作用于5-HT受体实现其对子宫收缩活性的影响。本研究探讨巴西苏木红素对5-HT受体的作用及其特点。方法:小鼠分离子宫平滑肌条,采用受体拮抗实验和real time PCR方法,对巴西苏木红素的5-HT受体的抑制作用进行研究。结果:巴西苏木红素虽然对正常子宫平滑肌的收缩幅度和频率无影响,但能明显抑制5-HT2受体激动剂马来酸麦角新碱的收缩活性,其pA2为5.71±0.21。而5-HT亚型的选择性激动剂舒马普坦(5-HT1D)、AL34662(5-HT2A)、MCPP(5-HT2C)的收缩子宫活性同样能够被巴西苏木红素抑制,pA2分别为4.58±0.06;4.91±0.15;5.38±0.15。巴西苏木红素明显抑制了5-HT受体1D和2C亚型mRNA的表达。结论:巴西苏木红素能够阻滞小鼠子宫5-HT受体,并通过可能影响5-HT受体所介导的子宫功能。
