炎症性肠病小鼠模型的建立及其影响因素探讨

Establishment of Inflammatory Bowel Disease Models in Mice and Investigation of its Influencing Factors

目的:通过单次灌肠和皮肤致敏联合灌肠,构建2,4,6-三硝基苯磺酸(TNBS)诱导的炎症性肠病小鼠模型,探讨最佳造模方法,并分析影响模型构建的因素。方法:55只SPF雄性BALB/c小鼠随机分为7组,包括对照组、不同剂量TNBS(100、150、175、200、225 mg/kg)单次灌肠组及皮肤致敏联合灌肠组。于造模后5 d处死各组小鼠,观察结肠大体形态并评分;取病变处进行石蜡包埋切片,HE染色,并进行病理组织学评分。结果:100、150 mg/kg TNBS单次灌肠组动物未见明显的溃疡形成;其余剂量组动物均有不同程度的溃疡形成,成模率与剂量成正比,其中225 mg/kg剂量组动物成模率为100%,但病变较重、病变不均一且偶有小鼠眼睛失明的副作用出现。皮肤致敏联合灌肠组动物均有溃疡形成,成模率100%,病变适中且未发现小鼠眼睛失明的副作用。结论:175-225 mg/kg TNBS单次灌肠及皮肤致敏联合TNBS灌肠均可制备小鼠炎症性肠病模型,但皮肤致敏联合TNBS灌肠制备的炎症性肠病模型成模率高,病变适中,模型稳定,适合用作科学研究模型。

Objective： To compare two methods in establishing the 2,4,6-trinitrobenzene sulfonic acid（TNBS）-in-duced inflammatory bowel disease（IBD） mouse models. In the first one, only a single enema of TNBS was used; in the second one, the enema of TNBS combined with skin sensitization in advance was used. This study aims to explore the optimal method of building mouse models of IBD and analyze the factors affecting the establishment of IBD models. Methods： 55 SPF male BALB/c mice were randomly divided into 7 groups, including control group, single enema groups with different doses of TNBS（100, 150, 175, 200, 225 mg/kg） and the group of skin sensiti- zation combined with enema. The mice were sacrificed at day 5, and the colons were observed under a stereomi- croscope to evaluate the common morphological damage, and then embedded in paraffin to perform histological analysis. Results： In the groups with low doses of TNBS（100, 150 mg/kg）, there was no obvious ulcer formation in the colons. But in the groups with higher doses（175, 200, 225 mg/kg）, ulcers with different severity could be observed. The rate of ulcer formation was in direct proportion to the dosage of TNBS. In the dose of 225 mg/kg, the ulcer information was 100%. However, the lesions of the colon were very severe and disparity. Occasionally, some animals had a side effect of mouse blind. By contrast, in the skin sensitization combine enema group, the ul- cer information was also 100%, but the lesions were moderate, and there was no side effect was observed. Conclu- sion： This study demonstrated that the mouse IBD models could be established by using a single enema of TNBS in a dosage ranged from 175 to 225 mg/kg, or a skin sensitization combined with TNBS（150 mg/kg） enema. Rela- tively, with the later method, the resulted IBD models have moderate lesions, 100% ulcer formation rate with on side effect. This method is optimum in establishing mouse IBD models for scientific research.