两种溃疡性结肠炎大鼠模型的比较

Comparison of two experimental ulcerative colitis models in rat

目的:比较2,4,6-三硝基苯磺酸(2,4,6-trinitro-benzene-sulfonic acid,TNBS)与免疫复合法介导的溃疡性结肠炎(Ulcerative colitis,UC)动物模型的效果。方法:SD大鼠随机分为免疫复合法(Ⅰ组)、TNBS/乙醇(Ⅱ组)、乙醇对照(Ⅲ组)和生理盐水对照(Ⅳ组)。Ⅰ组先间隔2周给予兔肠黏膜制备的抗原乳化液(含抗原8 mg)免疫2次。4组均于禁食24h后用0.65ml不同液体灌肠:Ⅰ、Ⅱ组均为100mg TNBS/kg+50%乙醇;Ⅲ组为50%乙醇;Ⅳ组为生理盐水。造模后第1、21d,第8周、12周处死大鼠,观察大体病灶及光镜下组织形态学改变。结果:Ⅰ、Ⅱ组均出现糜烂、溃疡等典型UC结肠病变,Ⅰ组还伴有末段回肠病变;Ⅰ组的病变可维持8周,Ⅱ组病变3周后趋向愈合。Ⅲ组病变仅黏膜充血水肿和少量糜烂或浅表溃疡,第21d痊愈。Ⅳ组未见组织损伤。结论:免疫复合法重复性好,病变更类似人UC,持续时间长,是较理想的造模方法。

Objective：To compare the rat models of ulcerative colitis induced by 2,4,6-trinitro-benzene-suffonic acid（TNBS） and immune-comb method. Methods：SD rats were randomly distributed into group Ⅰ （immune-comb method）,group It （TNBS/ethanol）,group Ⅲ （50% ethanol） and group Ⅳ （control）. The rats in group Ⅰ were sensitized 2 times by antigen made of rabbit colon mucosa in 2-week intervals. After abrosia for 24 hours,each rat in four groups received enema of 0.65 ml different fluids,which were：TNBS 100mg/kg ＋50%ethanol for group Ⅰ and It ,50%ethanol for group Ⅲ ,and normal sodium for control group. Rats were sacrificed on day 1,21 and week 8,12 after enema to observe the macroscopical focus of infection in bowels and the microscopical changes. Results：The typical erosion and ulcer changes appeared in group Ⅰ and It ,and there was accompanying pathological changes in the end piece of ileum in group Ⅰ. The pathological changes for group Ⅰ could keep for 8 weeks,while those for group It trended to heal 3 weeks later. The pathological changes in group Ⅲ only were hyperemia, oedema and a few anabrosis or superficial ulcer, keeped for 21days. There was no tissue damage in group Ⅳ. Conclusion： Immune-comb method is comparatively the ideal method to establish the model, ,because it has a good reproducibility,a long persistence time, and the pathological changes resemble more to those of man..