丁酸钠溶液灌肠对大鼠内脏感觉的影响

对于肠易激综合征（IBS）内脏感觉功能异常的研究，需建立合适的动物模型。目的：以丁酸钠溶液灌肠建立大鼠结肠感觉过敏模型，观察其内脏感觉功能和结肠黏膜改变。方法：16只大鼠随机分为实验组和对照组。实验组予1 ml 200mmol／L丁酸钠溶液灌肠，对照组予1 ml 0.9％NaCl溶液灌肠，每天2次，连续3d。分别于灌肠前和实验开始后第3、6、9、12、15、18d行结直肠扩张（CRD），观察腹壁回撤反射（AWR）评分和内脏感觉压力闽值，以反映内脏感觉功能。实验结束后处死大鼠，行结肠黏膜大体形态观察和组织学检查。结果：实验第3-12d．实验组不同CRD压力下AWR评分均显著高于对照组（P〈0.05），疼痛感觉压力阈值显著低于对照组（P〈0.05）；第15-18d，上述指标恢复至初始状态。实验结束后,实验组与对照组结肠黏膜大体形态和组织学改变均无明显差异。结论：丁酸钠溶液反复灌肠可诱导大鼠结肠感觉过敏，内脏感觉功能恢复后，结肠黏膜改变同步恢复。该模型可用于IBS病理生理机制的研究。

Effect of Coloclysis with Sodium Butyrate Solution on Visceral Perception in Rats

Background： For studying the visceral hypersensitivity of irritable bowel disease （IBS）, a suitable animal model needs to be established. Aims： To establish a colon hypersensitivity model in rats by sodium butyrate solution coloclysis, and to observe the visceral perception and colon mucosal changes in that model. Methods： Sixteen rats were randomly divided into experimental group and control group, and were instilled in colon with 1 ml of 200 mmol/L sodium butyrate solution or 0.9% NaCl solution, respectively, twice a day for 3 days. Score of abdominal withdrawal reflex （AWR） and pressure threshold value of visceral perception after colorectal distension （CRD） were determined before and 3, 6, 9, 12, 15 and 18 days after the starting of coloclysis. Rats were sacrificed at the end of the experiment. The gross morphological and histological changes of colon mucosa were observed. Results： Under various CRD pressures the AWR score was significantly higher and the pressure threshold value of pain perception was significantly lower in experimental group than those in the controls at the 3rd, 6th, 9th and 12th day of the experiment （P〈0.05）, and returned to the initial status at the 15th and 18th day. At the end of the experiment, no significant differences were found in gross morphological and histological changes of colonic mucosa between the experimental and control groups. Conclusions： Repeated coloclysis with sodium butyrate solution can induce colon hypersensitivity in rats, and colon mucosal changes recover in parallel with the normalization of visceral perception. This visceral hypersensitivity model can be used in the studies of pathophysiologic mechanism of IBS.