氨甲喋呤诱导的大鼠持续性肠黏膜损伤模型的建立与评价

Establishment and assessment of a rat model of persistent intestinal mucosal injury induced by methotrexate

目的建立一种大鼠肠黏膜持续损伤模型。方法采用两次腹腔注射氨甲喋呤（methotrexate、MTX）建立大鼠肠黏膜持续损伤模型。实验期间记录进食量、体重变化,HE染色进行病理学分析,分析血浆中的D-乳酸（D-lactate）、二胺氧化酶（diamine oxidase,DAO）及小肠组织中的髓过氧化物酶（myeloperoxidase,MPO）、丙二醛（malonaldehyde、MDA）水平。结果造模后,大鼠体重减轻、摄食量减少,第4天大鼠小肠组织损伤评分（Chiu评分）均明显升高（P〈0.05）,D-乳酸含量、DAO与MPO活力、MDA含量均显著升高（P〈0.05）。第5天大鼠开始恢复,在第6天时空白组基本恢复正常。第二次注射后,大鼠症状与第一次相似,损伤后再次恢复,第12天基本恢复正常。结论 20 mg/kg MTX诱发的大鼠肠黏膜损伤是一个急性损伤过程,整个病程大约为4~5d,适用于药物治疗评价;两次间歇式10 mg/kg注射MTX可以造成大鼠肠黏膜的持续损伤,由此成功建立肠黏膜持续损伤大鼠模型。

Objective To establish a rat model of persistent intestinal mucosal injury. Methods The rat model of persistent intestinal mucosal injury was induced by intraperitoneal injection of methotrexate. The food intake and body weight of all the rats were recorded. Pathological changes were observed using HE staining,the level of D-lactate and diamine oxidase in plasma,and myeloperoxidase and malondiadehyde in the intestinal tissue were measured by biochemistry.Results After modeling,the rat body weight and food intake were decreased. On day 4,the scores of mucosal damage,the levels of plasma D-lactate,DAO,MPO and MDA were significantly increased（ P〈0. 05）. On day 5,the intestinal damages of rats began to restore,and there was no significant difference among groups on day 6. The symptoms after the secondary injection were similar to those after the first injection,and the rats recovered gradually at day 12. Conclusions Intestinal mucosal injury in rats induced by 20 mg / kg MTX is an acute injury process,the course only lasts for 4- 5 days.Intermittent injections twice of 10 mg / kg MTX can cause persistent intestinal mucosal injury in rats. This persistent injury model is more suitable for nutritional therapy evaluation in medium-and long-term studies of nutritional therapy.