溃疡性结肠炎大鼠氧自由基动态变化及肠黏膜超微结构观察

Dynamic alteration of oxygen radicals in ulcerative colitis model and ultrastructure ovservation on intestinal mucosa

目的探讨氧自由基在溃疡性结肠炎发病中的动态变化,并评估其与肠道损伤的相关性。方法将SD大鼠随机分为正常对照组、模型1、模型2组,每组10只。正常对照组不进行药物干预,模型1和2组以三硝基苯磺酸和无水乙醇灌肠制作溃疡性结肠炎大鼠模型,分别在实验第8天、第4天、第8天宰杀取标本,检测血清中活性氧、超氧化物歧化酶以及丙二醛的动态变化,并与肠黏膜损伤指数做相关性分析。结果模型组血清中活性氧、丙二醛以及损伤指数于第4天开始升高,超氧化物歧化酶则在第4天降低,在第8天有所回升,但没有达到正常水平(<0.01)。模型组肠黏膜线粒体肿胀变圆球形且内容物有缺失,嵴略肿胀并有缺失;线粒体数量有减少。结论TNBS诱发的溃疡性结肠炎大鼠中,氧自由基参与其急性发病,肠黏膜线粒体受到损伤。

Objective To determine the dynamic alteration of oxygen radicals in ulcerative colitis model, and to evaluate their correlation with the degree of injury of the intestinal mucosa. Methods Thirty healthy adult SD rats were divided into group control, group model 1 and model2, and each group had 10 rats. The controls were fed with routine grains, while rats of model 1 and 2 were made as ulcerative colitis using trinitrobenzenesulfonic acid and pure alcohol. Each group were killed on the 8th, 4th and 8th day. The levels of ROS, superoxide dismutase （SOD） and malondialdehyde （MDA） in blood serum were detected. Their correlations with intestinal injury index were also analyzed. Results On the 4th day, the SOD level was increased in the TNBS model group ROS and MDA levels in the blood serum were decreased but On the 8th day, SOD level was elevated, but didn＇t reach the normal level （P〈0.01 respectively）. The electronic microscopy from the intestinal membrane of the model group showed a significant injury in the mitochondria, presented with swollen and ball shape, and the content and number were decreased. The cristae of mitochondria were also swollen, and some were lack of. Conclusion In TNBS- induced ulcerative colitis rat models, the oxygen radicals participated in the acute pathophisiology, and the mitochondria in the intestinal mucosa were injured.