The Establishment Of A Rat Model Of The Diarrhea Irritable Bowel Syndrome And Experimental Research On Treating Model Rats Of Irritable Bowel Syndrome With Tongxieyaofang

Objective: To explore the pathogenesis of irritable bowel syndrome (IBS) and the mechanism of curing experimental rat model of IBS in Tongxieyaofang.Method:1. The animal we choosed is neonatal SD rats. Model rats of IBS were prepared by chronic stimulation in colon and stimulation on tails. The model was established by intrarectal stimulation of acetic acid daily in the neonatal rats between postnatal 8 and 21days for two weeks. Then, stimulation on tails with forceps clip was given for 7 days. The threshold of abdominal withdrawal reflex (AWR) was evaluated during rectal distention at post 7, 9, and 10 weeks respectively, and the changes of rectal sensitivity were identified by the abdominal electrical activity measured at postnatal 12 weeks to prove the sucssess of the method of model.2. When the model of IBS was sucssessful, model rats of IBS were randomly divided into six groups: the low dosage of Tongxieyao- Fang group (GroupA), the middle dosage of Tongxieyaofang group (Group B), the high dosage of Tongxieyaofang group (Group C), the sibamin of Western medicine group (Group D), the addition of the normal control group (Group E) with the model group(Group F).Different group received oral administration of different treatment in a different dose for one month with twice in day. The respective dose of group A,B,C,D,E,F is 0.4ml/100g(4g/kg/d ),1.2ml/100g(12g/kg/d),4ml/100g(40g/kg/d),4ml/100g(150g/kg/d),4ml/100g(40g/kg/d),4ml/100g(40g/kg/d).And then ,We should Observe the bulgy capability of the sacculus that cause uplift- ing of abdomen and arching of back and the time of contract about abdomen muscle in rats.The level of substance P(SP),calcitonin gene related peptide(CGRP) in plasma and mucosa were evaluated. The Results were analyed by statistican. Results:1. In contrast to neonatal rats subjected to saline intrarectally (C group) and neonatal rats subjected to acetic acid intrarec- tally (B group), neonatal rats subjected to acetic acid intra- rectally and stimulated with forceps clip on tails (A group) showed a significant decrease in the volume threshold of abdo- men lifting and body arching during rectal distension(P<0.01). There was a significant increase of abdominal electrical acti- vity responding to 0.3, 0.6, and 0.9mL distention volume. (Compared with B group P<0.05, P<0.05 and P<0.05, respectively. Compared with C group P<0.01, P<0.05 and P<0.05, respectively)2. After treatment, tongxieyaofang and Sibamin were able to make intestinal behavioral and electrophysiological indicators induced after sensitization returned to normal, there is no difference between the high dosage of Tongxieyaofang group and the group of Sibamin. But there is no obvious recovery in the low dosage and the middle of Tongxieyaofang group.It can't reached statistical significance. The level of substance P in plasma of the model group rats increased significantly.The high dosage of Tongxieyaofang group and the group of Sibamin were able to make the level of substance P descends signify- cantly. And there is no difference between the high dosage of Tongxieyaofang group and the group of Sibamin.The level of substance P in mucosa of bowel of the model group rats increased significantly. The high dosage of Tongxieyaofang group.the middle dosage of Tongxieyaofang group and the group of Sibamin were able to make the level of substance P in mucosa of bowel descend significantly. And there is no difference in the three groups.The level of CGRP in plasma and mucosa of the model group rats descends significantly.The high dosage of Tongxieyaofang group were able to make it increase significantly.But there is no mutation in the low dosage of Tongxieyaofang group,the middle dosage of Tongxieyaofang group and the group of ShibaminConclusions:1. Chronic rectal irritation and stimulation with forceps clip on tails in the neonatal rats may lead to chronic rectal hypersensitivity in the adulthood. Stress and infection have synergistic effect in causing intestinal motility disorder. Stress makes the infective intestinal tract easier to be intestinal motility disorder, and the infective intestinal tract has stronger responding to stress. All those are in the absence of identifiable rectal pathological changes, which conforms to IBS.2. Tongxieyaofang was able to make intestinal behavioral and electrophy siological indicators induced after sensitization returned to normal. The level of substance P increased significantly.It play an important role in the pathogenesis of IBS. IBS can lead to the level of calcitonin gene related peptide in plasma and mucosa descends significantly. Tongxieyaofang was able to make the level of substance P in plasma and mucosa descends significantly and make the level of calcitonin gene related peptide in plasma and mucosa increased significantly.But sibamin only make the level of substance P in plasma and mucosa descends significantly, it had no any influence in CGRP.The possible mechanism of Tongxieyaofang: It makes substance P in plasma and mucosa descends significantly and makes CGRP in plasma and mucosa increased significantly. It cuts down the excitability of the dorsal horn nerve fible to raise the threshold value of visceral pain .In the end,the effection of the high dosage of Tongxieyaofang group is better compare to the group of sibamin.