溃疡性结肠炎与湿热证溃疡性结肠炎大鼠模型的比较研究

Comparative study of rat models with ulcerative colitis and ulcerative colitis plus damp-heat syndrome

目的建立适用于评价抗湿热证溃疡性结肠炎中药复方及新药研发药效的动物模型,并探讨普通溃疡性结肠炎(ulcerative colitis,UC)与湿热证UC的区别与联系。方法随机将24只SD大鼠分为空白对照组、UC组、UC+DH组,每组8只。除空白组外,UC组接受5%DSS诱导,而UC+DH组大鼠先后接受"高脂高糖饮食+饥饱交替+饮酒+高温高湿环境+5%DSS"诱导,为期29 d。每日观察大鼠的一般情况,进行疾病活动指数(disease activity index,DAI)评分和结肠组织病理评分(Geboes),血清生化检测各组大鼠的TG、CHOL、HDL_C、LDL_C、GLU、ALP、LDH、ALT、AST水平,检测血清中的DAO浓度和结肠中的MPO、MDA、GSH活性变化,ELISA法检测血清中的皮质醇含量及结肠中的HSPs、IL-10、TNF-α、MIP-1α、MIP-1β的表达。结果两种模型均出现不同程度的肠道炎症,DAI评分和Geboes指数增加,肝功能均存在不同程度的损伤情况。不同之处:与UC组相比,上述病理改变在UC+DH组大鼠上更为严重,除此,UC+DH组大鼠血清中的TG、CHOL、LDL_C、ALP、ALT、AST、DAO、皮质醇浓度明显增加,血清中HDL_C的浓度显著下降(P<0.05);结肠中HSPs、MPO、MDA、TNF-α、MIP-1α、MIP-1β的表达明显增加,结肠中的GSH和IL-10的水平明显降低(P<0.05)。结论两种UC模型均存在肠黏膜损伤和肝损伤情况。不同之处在于,湿热环境会加重DSS诱导的UC大鼠肠黏膜损伤程度,其机制可能与促炎、促脂质过氧化、提高肠黏膜渗透性有关。

Objective To establish an animal model suitable for evaluating the efficacy of an anti-damp-heat(DH)ulcerative colitis compound in Chinese medicine and for new drug development,and to explore the difference and connection between ordinary ulcerative colitis(UC)and UC with DH syndrome.Methods Twenty-four SD rats were randomly divided into the blank control group,UC group and UC+DH group.Rats in the UC group were induced by 5%dextran sodium sulfate(DSS),and the UC+DH group was induced by"high-fat and high-sugar diet+alcohol+hunger and satiety alternately+high temperature and humidity environment+5%DSS"for 29 d.The general condition of rats was observed every day for the disease activity index(DAI)and Geboes colonic histopathological scores.Serum levels of ALP,ALT,AST,CHOL,GLU,HDL-C,LDL-C,LDH and TG,and colonic activity of GSH,MDA and MPO were detected.Serum cortisol and colon expression of HSPs,IL-10,MIP-1α,MIP-1βand TNF-αwere detected by ELISA.Results The two models exhibited different degrees of intestinal inflammation,increased DAI and Geboes scores,and different degrees of damage to liver function.Compared with the UC group,pathological changes were more severe in the UC+DH group.In addition,serum levels of TG,LDL-C,ALP,ALT,AST,CHOL,cortisol,DAO,HSPs,MDA,MPO,MIP-1α,MIP-1βand TNF-α,and colonic levels of GSH and IL-10 were significantly increased in the UC+DH group,whereas the serum concentration of HDL-C was significantly decreased.Conclusions Intestinal mucosal injury and liver injury were found in both rat UC models.However,the hot and humid environment aggravated the degree of intestinal mucosal injury induced by DSS in UC rats,and its mechanism may be related to promoting inflammation,lipid peroxidation,and intestinal mucosal permeability.