葡聚糖硫酸钠致溃疡性结肠炎大鼠模型的建立

Establishment of dextran sulfate sodium-induced ulcerative colitis model in rats

目的: 建立大鼠溃疡性结肠炎(UC)模型. 方法: 给SD大鼠饮用40 g/L DSS溶液7 d,然后改正常饮水10 d. 每日进行疾病活动指数(DAI)评分. 于实验8,13和18 d分别处死4～5只,行组织学大体评分、组织病理评分及透射电镜观察. 计算盲肠、回盲部至肛门段结肠、胸腺、脾脏质量指数并测直肠髓过氧化物酶(MPO)含量. 结果:大鼠饮用40 g/L的DSS 7 d均出现腹泻、隐血试验阳性. 可见炎症主要累及黏膜和黏膜下层,部分表面上皮脱落,上皮内杯状细胞减少,隐窝破坏,浸润的炎症细胞以中性粒细胞为主. 伴有MPO升高[(8.84±3.67) nkat/g vs (127.19±27.84) nkat/g, P<0.01]及脾脏增大[(3.45±1.00) mg/g vs (5.07±1.31) mg/g, P<0.05]. 停药后症状及结肠病变逐渐恢复, MPO活性显著降低(P<0.05). 结论:此模型病理改变类似人UC.

AIM： To establish the rat model of ulcerative colitis （UC）. METHODS： The rats were first given 40 g/L dextran sulfate sodium （DSS） in drinking water for 7 d and then given only water for 10 d. The disease activity index （ DAI ） of all the rats was evaluated daily. The rats were killed on day 8, 13 and 18 and the lesion score and histological score of colon were evaluated. Segments of distal colon were adequately prepared for transmission electron microscopic observations. The weight index of cecum, colon, thymus and spleen were calculated and the myeloperoxidase （MPO） activity of rectum was measured. RESULTS： Rats receiving 40 g/L DSS solution for 7 d developed diarrhea and positive fecal occult blood. Inflammation of colon mainly involved the mucous membrane and submucosa. Focal erosions of the epithelium, goblet cells depletion, destruction of crypt and neutrophil infiltration were observed. The increase of MPO activity [ （ 8.84 ± 3.67 ） nkat/g tissue vs （127.19±27.84） nkat/g tissue, P〈0.01] and weight of spleen [（3.45±1.00） mg/g vs （5.07±1.31） mg/g, P〈 0.05 ] was also observed. After replacing the DSS solution with water, the symptoms and colonic pathological changes of rats were gradually disappeared and the MPO activity significantly decreased （ P 〈 0.05）. CONCLUSION： This colitis model in rats appears to share nearly all the morphological characteristics with human UC.