咳嗽变异性哮喘豚鼠模型的比较和评价研究

Comparison and Evaluation of Guinea Pig Models of Cough Variant Asthma

目的:比较三种咳嗽变异性哮喘豚鼠模型差异,探讨合适的CVA豚鼠模型以及模型评价标准。方法:将3周龄雄性Hartley豚鼠随机分为正常对照组、模型A组、模型B组,模型C组。在经典哮喘豚鼠造模方法基础上,模型A减少了2次致敏时卵蛋白的剂量,模型C在致敏之前给予环磷酰胺减轻致敏状态,而模型B采取腹腔注射与肌肉注射相结合的方法,卵蛋白浓度加倍,一次致敏;2周后均予以1%OVA溶液雾化,观察每组辣椒素诱导咳嗽次数、气道阻力变化、肺泡灌洗液中嗜酸性粒细胞百分比以及肺组织病理改变。结果:豚鼠咳嗽次数:模型A、B、C组的咳嗽次数均较空白对照组明显增多,差异有统计学意义(P<0.05),但是三组间的咳嗽次数差异无统计学意义(P>0.05)。豚鼠气道高反应性:在MeCh0.04mg/mL剂量下气道阻力A组>B组>C组,P<0.05。支气管肺泡灌洗液(BALF)中嗜酸性粒细胞百分比:模型A、B、C组的BALF中嗜酸性粒细胞百分比均较空白对照组明显升高,差异有统计学意义(P<0.05),以模型B组升高明显,但组间差异无统计学意义(P=0.051)。根据豚鼠肺部病理分级评分,3个模型组豚鼠的肺组织病理学评分明显升高(P<0.05),但组间比较,差异无统计学意义(P>0.05)。结论:三种模型咳嗽症状和气道高反应性大致符合CVA的临床症状的特征,其中模型A组与模型B组中出现4只明显喘息的豚鼠,模型C组的行为学表现和气道高反应性表现更为稳定,BALF中嗜酸性粒细胞比例,以及支气管病理切片结果接近于临床上CVA患者的临床特征。综上我们认为所建立的模型C组造模方法是可行方案中更为优化的。

Objective:To compare the differences in terms of airway responsiveness,airway inflammation and pathology among three cough variant asthma(CVA)guinea pig models,and to explore appropriate evaluation criteria to evaluate the advantages and disadvantages of each model.Methods:Three-week-old male Hartley guinea pigs were randomly divided into normal control group,model A group,model B group and model C group.Based on the classical asthmatic guinea pig modeling method,model A was given a reduced dose of ovalbumin during two sensitizations,model C was given cyclophosphamide prior to sensitization to reduce the sensitization state,while model B was given a combination of intra-peritoneal and intramuscular injections,the concentration of ovalbumin was doubled and sensitized once.After 2 weeks,three groups of guinea pigs were nebulized with 1%OVA.The number of capsaicin-induced coughs,changes in airway resistance,the percentage of eosinophils in alveolar lavage fluid and the pathological changes of lung tissue were observed in each group after nebulization.Results:Compared with the normal control group,the cough frequency of guinea pigs in model A,B and C groups was significantly increased,and the difference was statistically significant(P<0.05),but the cough frequency between the three model groups was not statistically significant(P>0.05).During the experimental observation,2 guinea pigs in both model A and model B had obvious wheezing cough respectively.When airway hyperresponsiveness in the guinea pigs was set at the dose of MeCh 0.04 mg/mL,the airway resistance was higher in group A than in group B than in group C(P<0.05).Compared with the normal control group,the percentage of eosinophils in the bronchoalveolar lavage fluid(BALF)of guinea pigs in the three model groups was significantly increased(P<0.05),with a significant increase in model B,but there was no significant difference between the three model groups(P=0.051).In each model group,the local mucosal epithelial injury in the bronchial wall of guinea pigs in each model group was shed off,congestion,edema and infiltration of a large number of inflammatory cells were observed in all layers of the bronchial wall.According to the pathological grading score of guinea pig lungs,the lung histopathological score of guinea pigs in the three model groups was significantly increased(P<0.05),but there was no statistically significant difference between the groups(P>0.05).Conclusion:The cough symptoms and airway hyperresponsiveness of the three models are roughly consistent with the characteristics of clinical symptoms of CVA.Amongst them,there were four guinea pigs in model A and model B with obvious wheezing.Model C's behavior and airway hyperresponsiveness were more stable,the proportion of eosinophils in BALF,and the pathological results were close to the clinical characteristics of CVA patients.Therefore,we believe that the established model C modeling method is feasible and more optimized.