逍遥散对肠易激综合征大鼠结肠5-HT受体的干预作用

Effect of Xiaoyansan on 5-Hydroxytryptamine Receptors in Rats with Irritable Bowel Syndrome

目的:研究肠易激综合征(IBS)模型大鼠结肠5-HT受体的异常变化,揭示IBS模型5-HT受体对内脏敏感性异常调节的途径及中药复方逍遥散的作用环节。方法:SD大鼠48只,随机分为正常组,模型组,逍遥散低、中、高剂量组和阳性对照组,以心理应激联合免疫诱导致敏法建立IBS模型。造模结束后各组大鼠分别灌胃给药,连续给药14天。评估球囊结直肠扩张引起腹部收缩反射(AWR)的最小容量阈值以反映模型大鼠内脏敏感性,采用酶联免疫法测定各组大鼠结肠黏膜5-HT3受体(5-HT3R)、5-HT4受体(5-HT4R)水平。结果:与正常组比较,模型组大鼠引起AWR的最小容量阈值、结肠黏膜5-HT 4受体(5-HT4R)水平降低,结肠黏膜5-HT3受体(5-HT3R)水平明显升高(P<0.05,P<0.01);逍遥散能升高IBS大鼠AWR最小容量阈值,降低结肠黏膜5-HT3R水平,升高结肠黏膜5-HT4R水平(P<0.05,P<0.01)。结论:逍遥散可能通过调节IBS模型大鼠结肠5-HT受体,减弱神经元兴奋性,从而提高内脏痛阈,消除肠道过敏。

Objective： To observe the effect of Xiaoyaosan on 5-hydroxytryptamine （5-HT）receptors in rats with irritable bowel syndrome（IBS） and the underlying mechanism. Method： Fourty-eight Spague Dawley rats were randomized into normal control group, model group, and low, middle and high-dose groups of Xiaoyaosan, and pinaverium bromide group. IBS model was established with psychological stress and immune induction. After modeling, administration of drugs and saline was given to the corresponding group for 14 days. Abdominal withdrawal reflex（AWR） was used to evaluate the bowel sensitivity. The expressions of 5-HT3 receptor（5-HT3R） and 5-HT4 receptor（5-HT4R） on the colonic mucosa were evaluated by ELISA. Result： Compared with the normal control group, AWR was reduced and the level of 5-HT4R was downregulated while the level of 5-HT4R was increased in the model group（P〈0.01）, All dosage of Xiaoyaosan increased AWR and the level of 5-HTaR while reduced the level of 5-HT3R as compared to the model group（all P〈0.01）. Conclusion： Xiaoyaosan may decrease bowel sensitivity by regulating 5-HT receptors to reduce the neuron excitability.