2种诱导溃疡性结肠炎动物模型方法的比较

Comparison of Two Methods for Inducing Ulcerative Colitis in Animal Models

为比较小鼠经直肠给予或自由饮用葡聚糖硫酸钠(DSS)溶液后诱发溃疡性结肠炎的成模情况,本试验选取30只雄性C57BL/6J小鼠,随机分为正常对照组(WT组)、3%DSS自由饮用组(3%DSS组)和6 g/(kg·bw)DSS直肠给药组[6 g/(kg·bw)DSS组],每组10只,连续造模7 d。每天称重计算体重增长率,并进行小鼠疾病活动指数(DAI)评分。造模第8天解剖小鼠,分离结肠,测量结肠长度,H.E.染色观察组织病理学变化并进行组织病理学评分,免疫组织化学观察结肠上皮组织黏蛋白-2(MUC2)的表达并计算组织化学评分(H-score),分离脾脏并称重,计算脾脏指数。结果显示,与WT组比较,DSS造模组小鼠的体重和结肠上皮组织MUC2的H-score极显著下降(P<0.01);DAI评分、病理学评分和脾脏指数极显著升高(P<0.01),结肠长度极显著缩短(P<0.01);与3%DSS组比较,6 g/(kg·bw)DSS组小鼠的体重和结肠上皮组织MUC2的H-score显著下降(P<0.05),DAI评分和脾脏指数显著升高(P<0.05),病理学评分极显著升高(P<0.01),结肠长度显著缩短(P<0.05)。结果表明,小鼠自由饮用3%DSS和直肠给予6 g/(kg·bw)的DSS溶液均可建立溃疡性结肠炎模型,其中6 g/(kg·bw)DSS造模症状较重、均一性较好且DSS用量较少。

In order to compare the effectiveness of inducing ulcerative colitis in mice through rectal administration or free drinking to dextran sulfate sodium(DSS)solution,this study utilized 30 male C57BL/6J mice,randomly divided into the Normal control group(WT group),3%DSS free drinking group(3%DSS group),and 6 g/(kg·bw)DSS rectal administration group[6 g/(kg·bw)DSS group],with 10 mice in each group.The models were induced continuously for 7 days.Weigh the mice daily to calculate the rate of weight gain and assess the disease activity index(DAI)for the mice.On the 8th day post-modeling,mice were dissected,and the colon was isolated,the colon length was measured,H.E.staining was performed to observe the histopathological changes and assign scores,and immunohistochemistry was conducted to observe the expression of Mucin-2(MUC2)in colonic epithelial tissues,and H-score was calculated.Spleen was isolated,weighed,and spleen index was calculated.The results showed that compared with the WT group,mice in the DSS-induced model groups exhibited extremely significant decrease in body weight and colonic epithelial tissue MUC2 H-score(P<0.01),while DAI scores,histopathological scores,and spleen indexes extremely significant increase(P<0.01),and colon length extremely significant decrease(P<0.01).Comparing with the 3%DSS group,mice in the 6 g/(kg·bw)DSS group had significant decrease in body weight and colonic epithelial tissue MUC2 H-score(P<0.05),significantly increased DAI scores and spleen indexes(P<0.05),and extremely significant higher histopathological score(P<0.01),with significant decrease in colon length(P<0.05).The results suggest that both free drinking of 3%DSS and rectal administration of 6 g/(kg·bw)DSS can establish an ulcerative colitis model in mice,with the 6 g/(kg·bw)DSS model showing more severe and consistent symptoms with a lower DSS dosage.