慢性束缚应激联合特殊饮食制备腹泻性肠易激综合征(IBS-D)大鼠模型的研究

Establishment of diarrhea-predominant of irritable bowel syndrome(IBS-D) model rats by chronic restraint stress and a specialized diet

目的观察饲料中的乳糖添加量、束缚时间和造模持续时间对腹泻型肠易激综合征(IBS-D)大鼠模型的影响,筛选一种较为理想的IBS-D大鼠模型的制备方法。方法将大鼠随机分为正常对照组、模型A组(30%乳糖+束缚1 h)、模型B组(30%乳糖+束缚1.5 h)、模型C组(45%乳糖+束缚0.5 h)、模型D组(45%乳糖+束缚1 h),以造模第7、10、14天腹壁回缩反射时的疼痛阈值评价其内脏敏感性,以腹泻指数评价其腹泻程度,同时以多道生理信号采集处理系统记录餐后1 h空肠平滑肌运动波,分析计算运动波振幅和频率,评价其胃肠动力。结果各组模型大鼠容量阈值在第7、10、14天均较正常对照组明显降低;腹泻指数在第7、10、14天均较正常对照组明显增加;其中模型D组发生较显著的平滑肌运动节律异常。结论在当饲料中乳糖比例在30%以上,束缚时间在1 h以上时,造模动物在7~14 d发生典型IBS-D的胃肠动力异常和内脏高敏感状态。

Objective To observe the effects of the lactose content in feed,the time duration of chronic restraint stress and the duration of modeling on the diarrhea-predominant of irritable bowel syndrome(IBS-D)model rats,and to select a preferred method for establishing the IBS-D rat model.Methods Rats were randomly divided into a normal control group,model group A(30%lactose+bound for 1 h),model group B(30%lactose+bound for 1.5 h),model group C(45%lactose+bound for 0.5 h),and model group D(45%lactose+bound for 1 h).The visceral sensitivity was evaluated with the pain threshold at the time of abdominal wall retraction on the 7th,10th,and 14th days after modeling.The diarrhea index was used to evaluate the extent of diarrhea.A multi-channel physiological signal acquisition processing system was used to record the wave in jejunum smooth muscle movement at 1 h after feeding.Wave amplitude,frequency analysis,and movement calculation were used to evaluate gastrointestinal dynamics.Results The capacity threshold in each model rat at 7,10,and 14 days was significantly lower than that in the normal control group.Diarrhea indexes at 7,10,and 14 days were obviously increased compared with the normal control group.Model group D had less significant abnormalities in rhythmic movement of smooth muscle.Conclusions When lactose in the feed is>30%with a time duration of chronic restraint stress for more than 1 h,gastrointestinal motility abnormalities and visceral high sensitive state of typical IBS-D occur in the model rats at 7-14 days after modeling.