三硝基苯磺酸结肠炎动物模型的建立

Establishment of Rat Colitis Model induced by Trinitrobenzenesulfonic Acid

目的：建立三硝基苯磺酸（ＴＮＢＳ）诱导的结肠炎动物模型，探讨炎症性肠病（ＩＢＤ）的发病机制。方法：每只实验组大鼠用０．８５ ｍｌ含３０ ｍｇ ＴＮＢＳ的５０％乙醇灌肠１次诱发远端结肠炎，对照组大鼠仅以５０％乙醇或ＴＮＢＳ盐水溶液灌肠。观察结肠大体形态和组织学改变，并检测肠粘膜髓过氧化物酶（ＭＰＯ）活性。结果：灌肠后第１～３周，实验组大鼠远端结肠表现为充血、水肿及溃疡形成，组织学以中性粒细胞浸润为主；第４～８周，溃疡逐渐愈合，组织学表现为淋巴细胞和浆细胞浸润；组织ＭＰＯ活性于ＴＮＢＳ／乙醇灌肠后第１天即开始升高，持续３周，第４周起明显降低。对照组大鼠结肠大体形态、组织学改变及ＭＰＯ活性在第１周即恢复正常。结论：ＴＮＢＳ／乙醇诱导大鼠远端结肠炎是一种较理想的ＩＢＤ动物模型，可作为研究ＩＢＤ发病机制及评估药物疗效的有益工具。

Background/Aims: To set up a trinitrobenzenesulfonic acid (TNBS)-induced colitis model in rat and to assess its value in research study of inflammatory bowel disease (IBD). Methods: 0.85 ml enema containing 30 mg TNBS dissolved in 50% ethanol was instilled into rats' colon to induce distal colitis. The control rats were instilled 50% ethanol or TNBS/saline alone. The macroscopical, histological changes of the colon and myeloperoxidase (MPO) activity of the mucosa were evaluated. Results: One week after the TNBS/ethanol enema, hyperemia, edema and ulceration of the colonic mucosa appeared with predominant infiltration of polymorphonuclear leukocytes in the distal colon. Four weeks after TNBS/ethanol enema, ulcers were healed macroscopically, and lymphocytes and plasma cells became predominant. The tissue MPO activity increased on the 1st day after TNBS/ethanol enema and lasted for three weeks, but declined four weeks afterwards. In contrast, macroscopical, histological changes and MPO activity returned to normal level in the controls within the 1st week. Conclusions: TNBS/ethanol induced rat distal colitis is an ideal model of IBD, and may serve as a tool for investigation of the pathogenesis and pharmaceutical effect of IBD.