维生素A缺乏大鼠致敏后免疫功能低下对肺炎的影响机制

目的探讨维生素A（VA）缺乏对致敏后免疫细胞发育、功能的影响机制。方法：低VA饲料喂养大鼠8周时用卵蛋白致敏并分组。VAS组隔天口服vA100u，治疗3次；VAD组与正常组口服大豆油。用免疫组织化学法观察细胞角蛋白19（CK19）、病理学检查肺与脾病理变化、ELISA法检查血清Th因子水平等。结果VAD组胸腺萎缩，胸腺上皮细胞（TEC）肥大、聚集、CK19少。血IL—10、IL-4、胸腺索a-1升高。肺感染病灶多，肺泡隔浸润细胞较少与红细胞渗出多。VAS组胸腺细胞增生，TEC内CK193上调，血IFN—γ水平较低、IL-4、IL-10明显下调。小气道单层纤毛柱状上皮正常，管壁淋巴细胞浸润较重，肺泡区巨噬细胞多、渗出红细胞少。结论VA缺乏并致敏后胸腺TEC、胸腺细胞等发育和功能异常。补充VA改善胸腺TEC结构、促进淋巴细胞增生与非特异免疫功能，保护呼吸道黏膜与肺泡上皮。

EFFECT MECHANISM OF VITAMIN A DEFECT ON LOW IMMUNE FUNCTION IN RATS AFTER SENSITIZATION AND PNEUMONIA

Objective Discussion of vitamin A （VA） defect of sensitized immune cell development, function of the mechanism. Methods Low VA diet for 8 weeks when rats ovalbumin sensitized and division. VAS group the next day of oral VA 100u, the treatment of three times; VAD group and normal group oral soyabean oil. By immunohistochemistry was observed cytokeratin 19 （CK19）, histopathological examination of lung and splenic pathologic changes, ELISA method to check the level of serum Th factors. Results VAD group thymic atrophy, thymic epithelial cells （TEC） hypertrophy, together, CK19 less. Blood IL-10, IL-4, thymosin α1 increased. Many pulmonary infection lesions, less infiltrating cells and many red exudation blood cells in alveolar septa. VAS Group Thymocytes proliferation, TEC within CK19 increase low blood levels of IFN-γ, IL-4 and IL-10 significantly reduced. There were normal small airway ciliated columnar epithelium monolayer, heavier infiltrating lymphocytes into wall, many macrophages and low red blood cell exudation in alveolar areas.Conclusion VA defect and allergize resulted in abnormal function and development of thymic TEC and lymphocytes. Added VA to improve the thymic TEC structure. To promote lymphocyte proliferation and nonspecific immune function, protect the airway mucosa and alveolar epithelium.