过氧化氢酶对溃疡性结肠炎大鼠肠黏膜内细胞因子表达和NF-κB激活的影响

The effects of catalase on expression of cytokines and activation of nuclear factor κB in intestinal mucosa in rat with ulcerative colitis

目的观察过氧化氢酶(CAT)对大鼠溃疡性结肠炎(UC)的预防作用。方法用5%葡聚糖硫酸钠(DSS)制备大鼠UC模型;CAT灌肠,观察UC的症状和组织学变化;采用RT-PCR技术检测UC大鼠肠黏膜内TNF-α、IL-1β、IL-8的表达水平;应用免疫电泳迁移率改变分析(EMSA)法检测UC大鼠肠黏膜细胞NF-κB的激活情况。结果CAT预防组UC的症状、组织损害均较CAT治疗组、模型组明显减轻,同时TNF-α、IL-1β、IL-8的表达较CAT治疗组、模型组降低(P<0·05),NF-κB的核结合活性也降低,但较正常对照组仍明显升高。结论CAT对UC的发生有预防作用。

Objective To investigate the effects of catalase on expression of cytokines and activation of nuclear factor-κB in the intestinal mucosa in rat with ulcerative colitis（UC）. Methods UC was reproduced in rats with the oral innoculation of dextran sulfate sodium （DSS）. The expressions of TNF-α, IL-1β and IL-8 in the intestinal mucosa of rats were respectively determined by a semi-quantatitive assay, RT-PCR The activation of NF-κB in the intestinal mucosa were assessed with electrophoretic mobility shift assay （EMSA）. Results Comparing the mice challenged with DSS alone and to those treated with catalase, both symptoms and the lesions in the colonic mucosa were milder in the animals pretreated with catalase during the induction of colitis than that of control group and catalase treatment after induction of colitis group. Furthermore, the expressions of TNF-α, IL-1β, IL-8 were significantly down-regulated（P〈0. 05 ）. The activation of NF-κB was also suppressed. Conclusion Catalase had prophylactic effect on UC.