乙酸联合束缚应激对大鼠内脏敏感性及肠道肥大细胞状态的影响

目的：探讨腹泻型肠易激综合征动物模型的建立方法及模型评估。方法将30只成年SD大鼠随机分为乙酸刺激加束缚应激组（n＝10只），束缚应激组（n＝10只），和正常对照组（n＝10只）。采用乙酸刺激加束缚应激方法建立IBS动物模型，进行大便情况评估和直肠敏感性测试，盐酸甲苯胺蓝染色观察肠道肥大细胞数量及脱颗粒现象。结果在实验第7天，模型组大鼠粪便点数较正常组增多，差异有统计学意义（P＜0.05）；乙酸联合束缚应激组稀便数较其余两组增多，差异有统计学意义（P＜0.05）。乙酸联合束缚应激组大鼠直肠敏感性较其余两组增高，差异有统计学意义（P＜0.05）。乙酸联合束缚应激组大鼠肠道肥大细胞的数量较正常组增多，差异有统计学意义（P＜0.05），乙酸联合束缚应激组大鼠肠道肥大细胞可见脱颗粒现象。组织学分析显示各组大鼠均无明显的炎症性表现。结论乙酸联合束缚应激可增加大鼠内脏敏感性，并且使大鼠肠道肥大细胞数量增多，细胞脱颗粒现象增强。该综合造模方法能够较好的模拟人类IBS的发病形式，为我们进一步研究IBS的发生发展机制提供了理想的动物模型基础。

The effect of the method by jointing the chronic exterior stress of bondage with an intra colonic infusion of acetic acid stimulation to the visceral sensitivity in rats and the influence of the state of its colon mast cells

Objective The aim of this study was to explore the establishment method of an animal model of irritable bowel syndrome (IBS) and the evaluation of this animal model. Methods 30 adult SD rats were randomly divided into two groups: acetic acid irritation and bondage stress group (n=10),bondage stress group (n=10),and normal control group (n=10). The rats of the intervention group received an intra-colonic infusion of 0.4% acetic acid irritation combined with bondage stress to establish an animal model of IBS. The colonic sensitivity of the intervention group rats was assessed by stool test and colorectal distension (CRD) test. Hydrochloric acid toluidine blue staining was used to observe the number degranulation phenomenon of mast cells in the ileocecum. Results On the 7th day, the number of soft feces was 8 and loose stool was 4 in the model group, significantly higher than that in the bondage stress group(0 and 0) (P<0.05),and normal control group (1 and 0) (P<0.05). On the 10th day, when the AWR=2, the average rectal distension volume was 1.2 mL, significantly lower than that in the bondage stress group(1.37mL) (P<0.05),also significantly lower than in the normal control group (1.49 mL) (P<0.05), and when the AWR=4, the average rectal distension volume was 1.49 mL, significantly lower than that in the bondage stress group(1.74mL) (P<0.05),and the normal control group (1.77 mL) (P<0.05). These results indicated that the visceral sensitivity of the model group was significantly higher than that in the bondage stress group and normal control group. Histological analysis showed that the rats of all groups had no obvious inflammatory changes. Conclusions Chronic bondage stress combined with intra-colonic infusion of 0.4% acetic acid irritation can be used to increase the visceral sensitivity and amount and degranulation of mast cells in the intestinal tissue in rats. This established rat model shows pathogenetic changes resembling the pathogenesis of human irritable bowel syndrome, and provides a useful animal model for further studies of the pathogenesis of this disease.