摘要
目的:探讨大黄的主要有效成分番泻甙对小肠平滑肌细胞收缩的影响。方法:酶解法获取大鼠小肠环行平滑肌细胞,图像分析仪检测不同浓度的番泻甙对小肠环行平滑肌细胞的收缩作用,激光扫描共聚焦显微镜测定番泻甙对细胞内游离钙离子浓度[Ca2+]i的影响,然后测定番泻甙对Ach刺激的小肠环行平滑肌细胞收缩反应和细胞内[Ca2+]i变化的影响作用,通过免疫荧光实验检测番泻甙对RhoA的活化和空间转位的影响。结果:不同浓度的番泻甙对小肠环行平滑肌细胞没有直接收缩作用,对环行平滑肌细胞的[Ca2+]i也没有升高作用,但经番泻甙作用后,Ach引起的小肠环行平滑肌细胞的收缩剂量-反应曲线明显左移(P<0.05)。番泻甙可以促使RhoA的活化,从胞浆转位至胞膜,提高平滑肌细胞收缩的钙敏感性。结论:番泻甙没有直接收缩小肠平滑肌的作用,但可通过活化RhoA,提高小肠环行平滑肌的钙敏感性,与其他激动剂协同增强小肠的运动功能。
Objective To investigate the effect of sennosides on the contractility of small intestine smooth muscle cells Methods Smooth muscle cells were isolated from the circular layer of Wistar rats small intestine, the contractile response was measured by computerized image mierometry, the change of intracellular Ca^2 ＋ （[ Ca^2 ＋ ]i） stimulated by sennosides and that stimulatecd by Aeh after incubated with sennosides were evaluated using C^2 ＋ indicator Fluo - 3 AM on a laserscanning eonfecal microscope. The translecation of RhoA by sennosides was measured too. Results Sennosides with different concentrations couldn＇t contract small intestinal circular smooth muscle and did not show direct effects on the [ Ca^2 ＋ ]i of smooth muscle cells, but could increase the reactivity of smooth muscle cells to Ach. RhoA could be activated and translocated from eytosol to plasma membrane by sennosides. Condusion Sennosides can not stimulate contraction of small intestine smooth cells directly, but can increase Ca^2＋ -sensitization of contractile apparatus which facilitate the effects of other agonists.
出处
《中国中西医结合外科杂志》
CAS
2007年第1期59-61,共3页
Chinese Journal of Surgery of Integrated Traditional and Western Medicine
关键词
番泻甙
小肠平滑肌细胞
钙敏感性
sennosides, smooth muscle cell of small intestine, Ca^2 ＋ -sensitization
