中文摘要：

目的：探讨二十碳五烯酸（EPA）对热打击后肠黏膜上皮细胞通透性改变的影响.方法：使用Caco-2细胞株建立肠上皮细胞紧密连接模型,加入25、50、100、150 μmol/L EPA培养96 h,进行43 ℃ 1 h的热打击.分别使用CCK-8法检测细胞增殖,transwell测定单层跨膜电阻抗（TEER）值和对大分子物质辣根过氧化物酶（HRP）的通透性,Western blot法检测occludin蛋白的表达水平,显微镜下观察考马斯亮蓝染色细胞骨架的变化.结果：50 μmol/L的EPA促进细胞增殖的效果最强,升高TEER和防止HRP通透性升高的作用最大（与其他各浓度组比较,P均〈0.01）,对occludin表达的增加作用最明显,并有益于维持细胞骨架的正常结构.结论：50 μmol/L的EPA能够保护肠上皮紧密连接,对肠黏膜屏障有一定的保护作用.

英文摘要：

Objective：To discuss the effect of eicosapentaenoic acid （EPA） on tight junction （T J） dysfunction of intestinal epithelium after heat stress. Methods： Human intestinal epithelial Caco-2 cells were pre-incubated with various concentration of EPA （25,50,100,150 μmol/L） for 96 hours, and then they were exposed to a temperature of 43 ℃ for 1 hour. Cell counting kit-8 （CCK-8） assay was used to detect the cellular proliferation. The barrier integrity of TJ was measured by detecting transepithelial electrical resistance （TEER） and horseradish peroxi- dase （HRP） permeability with transwell. Level of TJ protein occludin was assayed by Western blot. Change in cytoskeleton was observed by microscopy after Coomassie blue staining. Results： EPA in 50 μmol/L concentration showed the most effective effects on promoting cell proliferation, and a decrease in TEER and impairment of intestinal permeability induced by heat exposure （all P ~ 0.01） were attenuated as compared to the other concentration groups. The function of occludin expression was most significantly elevated by 50 μmol/L EPA. The distortion of cytoskeleton was also effectively prevented by pretreatment with 50μmol/L EPA. Conclusions. This study indicates that 50 μmol/L EPA is potent in protecting intestinal epithelial barrier function against heat-induced permeability dysfunction and damage of tight junction.