肠易激综合征大鼠内脏高敏感性与脑肠互动的研究

目的研究腹泻型肠易激综合征大鼠模型内脏敏感性的改变与c-fos在结肠及中枢神经系统异常表达的关系。方法采用乙酸灌肠法造成腹泻型肠易激综合征动物模型（A组,n=12）和对照组（B组,n=12）,造模后通过腹部回撤反应评分评价内脏敏感性;用印度墨汁肠道染色法观察小肠蠕动,以墨汁在小肠中移行的距离占整段小肠长度的百分比来观察小肠推进蠕动的变化;应用免疫组织化学染色及计算机图像分析系统半定量分析结肠及中枢神经系统c-fos表达。结果该模型符合腹泻型肠易激综合征特征,A组腹部回撤反应评分、结肠及中枢神经系统c-fos表达高于B组,两组差异有统计学意义（P〈0.05）。结论乙酸灌肠法造成腹泻型肠易激综合征大鼠模型内脏高敏感性,c-fos的高表达参与大鼠内脏高敏感的异常调节。

The investigation of the relation between visceral hypersensitivity and brain-gut interac- tion in the rat model with irritable bowel syndrome

Objective To study the interaction of the visceral hypersensitivity and the abnormal ex- pression of c-fos in the colon and central nervous system in the rat model of diarrhea-predominant irritable bowel syndrome. Methods The rat model of diarrhea-predominant irritable bowel syndrome was induced by the intra- colonic administration of acetic acid. The visceral sensitivity was evaluated by the score of abdominal withdrawal reflexes in the model group （ group A,n = 12） and the control group （ group B ,n = 12） . A colored marker （ in- dian ink） was employed for the measurement of small intestinal transit. The expression of c-fos in the colon and central nervous system was detected by an immunohistochemical staining and was analyzed semi-quantitatively by computerized color image analyzer. Results The character of this model matched the character of diarrhea~ predominant irritable bowel syndrome. The score of abdominal withdrawal reflexes in group A was significantly higher than that of group B （P 〈 0.05）. Also, the expression of c-fos in the colon and central nervous system in group A was greater than that of group B （ P 〈 0.05）. Conclusion Th~ rat model of diarrhea-predominant irri- table bowel syndrome which was established the intracolonic administration of acetic acid shows the character of visceral hypersensitivity. And the hyperexpression of c-fos in the colon and central nervous system is probably involved in the pathophysiology of visceral hypersensitivity.