不同剂量过敏原对滴鼻制备急性和亚急性小鼠哮喘模型的影响

Effects of different doses of allergen on acute and subacute mouse models of asthma

目的:评估不同剂量过敏原对滴鼻制备小鼠急性和亚急性哮喘模型的影响。方法:将不同剂量卵清蛋白(OVA)25μg、50μg、100μg连续滴鼻,建立急性和亚急性小鼠哮喘模型。使用有创小鼠肺功能仪测量各组小鼠肺功能参数;收集小鼠肺泡灌洗液计数细胞总数和细胞分类;取其肺组织常规石蜡包埋切片,进行伊红染色(HE)、刚果红染色、马松染色和过碘酸雪夫氏(PAS)染色,观察炎性细胞浸润,胶原纤维沉积、黏液分泌等指标的变化。结果:在实验第20d和24d,100μg与50μgOVA激发组小鼠气道反应性、肺泡灌洗液中细胞总数和嗜酸性粒细胞百分比增高;小鼠肺泡、管腔、管壁及伴行动脉周围有大量炎性细胞特别是嗜酸性粒细胞浸润,支气管粘膜皱襞增多、延长,管腔内存有大量黏液性痰栓;支气管管壁及其伴行动脉周围胶原纤维沉积明显增加;气道粘蛋白染色成强阳性反应,较25μgOVA激发组和生理盐水组小鼠有明显差异。结论:采用不同剂量OVA滴鼻,成功建立了程度不同的急性和亚急性小鼠支气管哮喘模型。过敏原剂量对模型建立有重要影响,为进一步研究哮喘的发生机制和药物筛选奠定了基础。

Objective： To evaluate effects of different doses of allergen on ovalbumin （OVA）-induced acute and sub-acute mouse models of asthma by intranasal challenge. Methods： In brief, intranasal inhalation challenge with different doses of OVA （25, 50 and 100μg, respectively） was performed to induce acute and sub-acute mouse models of asthma. The respiratory function parameters of excited group and control group were measured using an invasive pulmonary function device. After collecting bronchoalveolar lavage fluid （BALF） of each group the cells were counted. Histological staining with HE, Congo red, Masson and Periodic acid-Schiff （PAS） were employed in paraffin-embedded sections derived from the left lungs to identify inflammatory cell infiltration, collagen deposition, mucus expression and other indicators. Results： Compared with 25 μg OVA- challenged group and saline group, at day of 20, 24, 100 and 50μg OVA-challenged groups showed the bronchial hyperresponsiveness and the elevated numbers of inflammatory cells including eosinophils in BAL fluid, the alveolar and bronchial wall, as well as in bronchial lumen and blood vessels. Bronchial mucosal folds were increased, extended and thickened, with a large amount of mucous sputum plugs in the bronchial lumens and significant deposition of collagen fibers in the bronchial and blood vessels. Additionally, PAS staining showed increased mucus in bronchial lumen. Conclusion： With different doses of intranasal inhalation of OVA, we successfully established varying degrees of acute and sub-acute mouse models of asthma. Our studies provided the foundation for further research on the pathogenesis and drug screening of asthma using mouse models.