食物过敏动物模型中小肠的变化

 【目的】应用卵蛋白致敏Nc／Jic雄性小鼠建立食物过敏动物模型，探讨食人过敏原后小肠黏膜的形态学及免疫学的变化。【方法】选取Nc／Jic雄性28只，分为两组，实验组小鼠21只，用卵蛋白（OVA）致敏，OVA（2mg／mL）经肠道攻击1h、6h、24h后分别采血及小肠，对照组7只，用生理盐水代替OVA，处死小鼠取小肠。对小肠样本进行染色，在高倍镜下观察小肠的形态学和细胞学变化，计数100个细胞并对肥大细胞、嗜酸细胞和淋巴细胞等炎性细胞进行分类：用免疫组织化学染色法（S-ABC法）检测小肠黏膜细胞因子IL-4、IL-6，分析小肠黏膜免疫学的变化。【结果】相对于对照组，实验组小鼠小肠黏膜H＆E染色可见小肠黏膜水肿及炎性细胞浸润，1h以肥大细胞为主（P〈0．05），6h在小肠黏膜可见到大量嗜酸性细胞浸润（P〈0．05）．而24h则以淋巴细胞为主（P〈0．05）。免疫组织化学染色显示在OVA致小鼠的小肠黏膜中，IL-4及IL-6阳性细胞数明显高于对照组（P〈0．05）。【结论】比较对照组，在食物过敏时Nc/Jic雄性小鼠小肠黏膜不仅在形态学呈现免疫炎症反应及损伤，而且在免疫学方面出现Th2细胞因子占优势的明显变化。

Alteration of Small Intestine in a Food Allergic Animal Model

Objective To investigate morphological and immunological alterations of intestinal mucosa in Nc/Jic male mice after feeding with the allergen of sensitized ovalbumin(OVA) to establish a food allergic animal model.Methods Twenty-eight Nc/Jic male mice were selected and separated into two groups.There were 21 mice in the management group and feed with OVA(the concentration was 2 mg/ml) for 1 h,6 h,and 24 h,respectively.The control group was 7 mice who were feed with saline instead of OVA for the same length of time.Then,the small intestines and blood samples were taken after treatments in both groups.The morphological and cytological changes of the small intestine tissue samples were stained and observed under a microscope.A hundred of the cells were counted and the inflammatory cells were classified into mast cells,eosinophil,and lymphocytes,cytokine IL-4 and IL-6 were examined using an immunohistochemical method(S-ABC) and their alterations in intestinal mucosa were analyzed.Results Compared with the control group,the mucous membrane edema in small intestines and inflammatory cells were observed in the management group after HE staining,Mast cells were major inflammatory cells 1 h after OVA oral challenge(P< 0.01).After 6 h,eosinophil infiltrated into the intestinal mucosa and became major inflammatory cells(P< 0.01) and after 24 h,lymphocytes became a major inflammatory cell type(P< 0.01).Moreover,IL-4 and IL-6 positive cells were significantly increased in the management group,compared with the control group(P< 0.05).Conclusion Compared to the control,the intestinal mucosa of Nc/Jic male mice showed morphological changes including inflammatory reaction and damage after feeding on allergens.In addition,immunological evidence indicated that Th2 cytokine clearly increased.