生大黄对大鼠离体肠管电活动和收缩活动的影响

本实验观察了生大黄对46只大鼠离体肠管电活动和收缩活动的影响,从电生理角度对其泻下和收剑机制作了初步探讨,结果表明:大黄对整个结肠电活动有明显兴奋作用,兴奋的特点为群集性放电,峰电频率明显增快(51.4±12.31C/min),幅度明显增高(2.8±0.49mv,p<0.01)。小剂量大黄可使肠电抑制,大剂量使则肠电兴奋。大黄也可使十二指肠峰电频率增快(由12.3±4.64C/min,增加到22.5±9.68C/min.)。阿托品可阻断大黄对肠管的兴奋效应,提示大黄是通过作用于肠管中M受体而实现其泻下作用的。

Effects of Rhubarb on Electrical and contractive activities of isolated Intestines in Rats

The effects of Rhubarb on electrical and contractive activities of isolated intestines in 46 rats were observed. The mechanisms of purgation and astringent based on point of view of electrophysiology were approached. The results indicate that electrical activity of colon (i, e. ascendens transversum, and descendens colon) is obviously excited by Rhubarb. The characteristic of excitement is cybotaxis discharge, and the frequency and amplitude of spike potential increase obviously (frequency 51.4±12.3c/min, amplitude 2.8±0.49mv, p<0.01). It is suggested that the purgation caused by Rhubarb is due to excite electrical activ ity of colon, block absorption of water and increase the discharge of content in colon. The electricai activity of colon which affected by various dose of Rhubarb was observed. Its regular pattern is inhibiting colon when smaller dose is used, and exciting it with larger dose. Spike potential frequency of duodenal excited by Rhubarb is increased(from 12.3±4.64c/min. to 22.5±9.86c/min, p<0.01). On the other hand, the exciting effect of Rhubarb on colon can be blocked by atropine, and it is supposed that purgation Caused by Rhubarb is due to the action on M-receptor in colon.