NO、NOS在大鼠实验性结肠炎中的动态变化及意义

Implication of dynamic changes of NO,NOS in rats of experimental colitis

目的 观察大鼠实验性结肠炎发生发展过程中一氧化氮 (nitricoxide ,NO)、一氧化氮合酶 (nitricoxidesynthase ,NOS)的动态变化 ,了解NO、NOS同大鼠实验性结肠炎的关系。方法 采用 2 ,4 二硝基氯苯 (2 ,4 dinitrochlorobenzene ,DNCB)诱发大鼠实验性结肠炎模型 ;Wistar雄性大鼠 70只 ,检测造模前 (Ⅰ组 ) ,造模后第 1天 (Ⅱ组 )、第 1周 (Ⅲ组 )、第 2周 (Ⅳ组 )、第 4周 (Ⅴ组 )结肠粘膜NO、NOS的动态变化 ,同时观察其病理改变 ;结果用 x±s表示 ,采用单因素方差分析对数据进行统计学处理 ,以P <0 .0 5作为差异有显著性的检验水准。结果 1、Ⅱ、Ⅲ、Ⅳ组同Ⅰ、Ⅴ组相比 ,结肠粘膜NOS的活性及NO的水平明显升高 ,经统计学分析差异显著(P <0 .0 1) ,而Ⅰ、Ⅴ组间上述指标差异无显著性 (P >0 .0 5 )。 2、病理学改变 :Ⅰ组未见明显病理学变化 ;Ⅱ、Ⅲ、Ⅳ组粘膜及粘膜下层明显充血、水肿 ,炎性细胞浸润 ,腺体杯状细胞减少 ,有糜烂及溃疡形成 ;Ⅴ组溃疡基本愈合 ,残存溃疡有明显修复性改变 ,如粘膜上皮修复、肉芽组织增生、瘢痕形成等。结论 NOS、NO过量生成和大鼠实验性结肠炎有关。

Aim To observe the dynamic changes of nitric oxide (NO), nitric oxide synthase (NOS) in the pathogenesis and development of experimental colitis in rats, and to investigate the relationship between experimental colitis and NO,NOS.Methods Rat model,induced by 2,4 dinitrochlorobenzene (DNCB),was used to explore the changes of NO,NOS.The levels of NO and NOS in colon mucosa were detected before the model was induced(Group Ⅰ),the first day(Group Ⅱ), the first(Group Ⅲ),second(Group Ⅳ),fourth(Group Ⅴ) week after the model was induced,respectively.Meanwhile,the pathological changes were observed.The results were represented as ±s and analysed statistically with one way analysis of variance (ANOVA). P <0.05 was considered of significance.Results 1?The levels of NO and activities of NOS in colon mucosa of the rats in Group Ⅱ, Ⅲ, Ⅳ were significantly higher than those in Group Ⅰ,Ⅴ ( P <0.01),but there was no significant difference between group Ⅰ and Ⅴ ( P >0.05).2?In rats of group Ⅱ～Ⅳ,obvious hyperemia, edema in colon mucosa and submucosa were found,and obvious infiltration of inflammatory cells,decrease of glandular goblet cells and formation of typical ulcer could be seen.While in group Ⅴ,there were few ulcers, and the remaining ulcers presented obvious recovering changes,such as recovery of mucosa, hyperplasia of granulation and cicatrization.Conclusion Excessive increase in the production of NO,NOS may contribute to occurrence of experimental colitis.