通过建立大鼠慢传输型便秘模型，检测便秘大鼠结肠5-HT的表达情况，探讨5-HT与慢传输型便秘是否存在相关性。

SD大鼠48只随机分为4组：空白组，模型组，莫沙必利治疗组，麻仁丸治疗组。空白组大鼠用生理盐水灌胃，便秘模型组和治疗组大鼠用复方地芬诺酯灌胃，建立大鼠慢传输型便秘（STC）模型。模型建立后，治疗组大鼠分别用莫沙必利、麻仁丸灌胃，观察各组大鼠大便粒数及大便湿重。治疗结束后将大鼠集体处死，取大鼠近端结肠标本，用免疫组织化学的方法检测各组大鼠结肠5-HT的表达情况。使用彩色病理图像分析系统对阳性表达的平均光密度值（MD）进行半定量分析。4组数据之间的比较采用方差分析。

免疫组化结果显示：便秘组结肠5-HT的MD值（0.453±0.028）大于空白对照组（0.148±0.011）、莫沙必利治疗组（0.316±0.012）及麻仁丸治疗组（0.291±0.010），t值分别为34.209、15.307、18.296，P均<0.001，差异有统计学意义；莫沙必利治疗组（0.316±0.012）和麻仁丸治疗组（0.291±0.010）的MD值均大于空白对照组（0.148±0.011），t值分别为35.983、31.919，P均<0.001，差异有统计学意义。

便秘大鼠结肠5-HT的表达增高，可能影响肠神经传导功能，从而导致便秘的发病。

To detect the expression of 5-HT in the colon of rats with constipation by establishing the model of slow transit constipation (STC), and to explore the correlation between 5-HT and STC.

Forty-eight SD rats were randomly divided into 4 groups: blank group, model group, mosapride group, maren pill group. The rats of blank group were given normal saline by gastric irrigation, while the rats of model group and treatment groups were given diphenoxylate by intragastric administration before treated. When established the model of STC, the rats of treatment groups were respectively given mosapride, maren pills, and the stool grain and stool wet weight were observed. The proximal colons were collected . Expression of 5-HT in the proximal colon by immunohistochemistry were detected. The staining results were analyzed semi-quantitively by computerized color image analyzer as the following parameter: mean density. Data were analyzed by ANOVA.

The density means (MD) of 5-HT in the colon of model group (0.453±0.028) was greater than the control group (0.148±0.011) (t=34.209, P<0.001), mosapride group (0.316±0.012) (t=15.307, P<0.001), maren pill group (0.291±0.010) (t=18.296, P<0.001), and the difference was statistically significant; The density means (MD) of mosapride group (0.316±0.012) (t=35.983, P<0.001) and maren pill group (0.291±0.010) (t=31.919, P<0.001) were higher than control group, which the difference was statistically significant.

The increased expression of 5-HT in the colon of rats with constipation may affect on the intestinal nerve conduction function, which led to the incidence of constipation.