SD幼鼠食物过敏模型的建立与评价

The establishment and evaluation of food allergy model in SD young rats

目的探讨采用卵白蛋白(OVA)低剂量腹腔注射基础致敏及高剂量灌胃激发建立SD幼鼠食物过敏模型的适宜条件,并对模型进行评价。方法 16只3周龄的雌性SD幼鼠随机分为过敏组和对照组,每组8只。实验第1天过敏组予腹腔注射OVA 40μg和氢氧化铝混悬液0.2 m(l氢氧化铝1 mg),第2、4、7、9、11天腹腔注射OVA 0.2 m(l40μg)进行基础致敏;第20、24、28、30天予OVA 2.0 m(l15 mg/ml)灌胃激发;对照组同期给予同等容量的生理盐水腹腔注射和灌胃。观察两组幼鼠肠黏膜嗜酸性粒细胞和肥大细胞密度、肥大细胞完整率及血清OVA-IgE含量变化。结果与对照组相比,过敏组幼鼠毛发无光、排稀便,血清OVA-IgE明显升高,差异有统计学意义(P<0.01);过敏组幼鼠空肠、回肠、结肠肠黏膜损伤,嗜酸性粒细胞浸润明显,肥大细胞聚集伴脱颗粒数目增多,差异有统计学意义(P<0.01)。结论采用致敏原OVA与免疫佐剂氢氧化铝,通过低剂量腹腔注射致敏联合高剂量灌胃激发所诱导的幼鼠模型与婴幼儿食物过敏临床特征、肠道病理改变一致,是一种理想的SD幼鼠食物过敏模型。

Objectives To explore suitable conditions for establishing food allergy model through sensitization by in- traperitoneal injection （i.p） with low-dose ovalbumin （OVA） and challenge by gavage with high-dose OVA in SD young rats, and to evaluate the model. Methods Sixteen three-week-old female SD young rats were randomly divided into two groups with 8 rats each. SD young rats in food allergy （FA） group were first sensitized by intraperitoneal injection with 0.2 ml suspension mixed with 40μg OVA and 1mg AI（OH）3 on the first day （d 0）, then intraperitoneally injected with 0.2 ml （40μg） OVA solution on days 2, 4, 7, 9 and 11, and lastly challenged by gavage with 2.0 ml （15 mg/ml） OVA solution on days 20, 24, 28 and 30. The rats in the control group were intraperitoneally injected and gavaged with the same volume of normal saline instead of OVA during the same period. The eosinophils （EOS）, mast cells （MC）, the integrity of MC in intestinal mucosa of two groups were observed, and ovalbumin specific IgE （OVA-IgE） levels in serum were analyzed. Results The rats in FA group had lusterless hair and diarrhea, and compared with control group, OVA-IgE levels were increased significantly （P〈0.05）. Compared with control group, the intestinal mucosa of jejunum, ileum and colon in FA group had more damage, with more EOS and degranu- lated MC aggregated （P〈0.01）. Conclusions The allergy model established through sensitization by intraperitoneal injection with low-dose OVA mixed with adjuvant AI（OH）3 and challenge by gavage with high-dose OVA in young rats had clinical features and intestinal pathological changes consistent with food allergy infants and it was an ideal food allergy model in SD young rats.