中文摘要：

目的：比较柠檬酸镁与乳糖用于建立SD大鼠慢性渗透性腹泻模型的可行性和实验适用性,为大鼠慢性渗透性腹泻模型的建立提供方法学基础。方法：5周龄SPF级SD大鼠31只,随机分为正常对照（Con）组、柠檬酸镁腹泻（Mg）组以及乳糖腹泻（Lac）组。Lac组用高乳糖饲料喂养,自由饮水;Mg组用基础饲料喂养,自由饮用柠檬酸镁溶液（镁离子浓度为4.77 g/L）,不另外给予普通饮用水;Con组用基础饲料喂养,自由饮水。每天观测大鼠的一般情况和腹泻情况,腹泻14 d后测试肌力和自主活动度。随后处死全部大鼠,取结肠中段检测肠黏膜跨肠上皮电阻;取小肠下段和结肠中段,HE染色观察肠黏膜病理学变化。结果：两腹泻组大鼠均出现体重增长缓慢、毛发稀疏无光泽、乏力、活动减少等临床表现,腹泻率和腹泻指数均显著高于Con组（P〈0.05）;Lac组腹泻指数明显高于Mg组（P〈0.05）,但Mg组小肠黏膜破坏程度较Lac组稍严重。结论：两种腹泻模型均能达到慢性腹泻的要求,但存在各自的优势,需根据实验需求选择恰当的模型。

英文摘要：

AIM： To compare 2 different rat models of chronic osmotic diarrhea with the lactose enrichment and magnesium citrate methods. METHODS： The SD rats（ n = 31） were randomly divided into lactose enrichment diarrhea group（ Lac group,12 rats）,magnesium citrate diarrhea group（ Mg group,12 rats） and normal control group（ Con group,7 rats）. The rats in Lac group were fed with a lactose enrichment diet and freely drank water. The rats in Mg group were fed with a standard diet and drank magnesium citrate solution. The Con group was fed with a standard diet and normal water. The general conditions and the characteristics of stool were observed every day. The grip strength and motor activity of the rats were measured after diarrhea for 14 d. The trans-epithelial resistance of the colonic mucosa was detected by Ussing chamber. The pathological changes of villus height and villus surface area in the intestine were observed with hematoxylin-eosin staining. RESULTS： The rats in both diarrhea groups displayed the clinical manifestations of slow increase in body weight,spare and dull hair,lacking in strength and physical inactivity. The grip strength and motor activity of the rats in both diarrhea groups decreased significantly compared with Con group. The diarrhea rate and diarrhea index of the rats in the 2 diarrhea groups were both significantly higher than those in Con group（ P 0. 05）. Moreover,the diarrhea index in Lac group was significantly increased compared with Mg group. The thickness of intestinal mucosa in Lac group was thinner than that in Mg group at the same time. However,the damage of intestinal villi in Mg group was more serious than that in Lac group. CONCLUSION： Both methods of lactose enrichment-induced diarrhea and magnesium citrate-induced diarrhea meet the requirement of chronic osmotic diarrhea,but there are different advantages between the diarrhea models. Therefore,we should select the correct diarrhea model to meet different aims of the experiments.