Objective To explore the effects of Aspergillus fumigatus(A. fumigatus) spores on airway inflammation and responsiveness in asthmatic rats.Methods Seventy male Wistar rats were randomly divided into Ⅰ and Ⅱ groups(n=35 in each group),then Group Ⅰ and Group Ⅱ were subdivided into a normal control group(n=5),an asthma group(n=10),a spores-treated control group(n=10),and a spores-treated asthma group(n=10).The rats were sensitized to ovalbumin(OVA) and challenged with aerosol OVA to establish the asthma model.The effects of A. fumigatus spores on asthmatic rats before and after OVA aerosol challenging were investigated in Group Ⅰ and Group Ⅱ,respectively.The parameters associated with bronchial epithelial damage were observed by total protein concentration in BALF measured by BCA method.Total and differential cell counts in BALF were also counted.The airway resistance and airway responsiveness were calculated by transpulmonary pressure and gas flow rate.Results In Group Ⅰ,the total protein in BALF in the asthma group treated with A. fumigatus spores before OVA challenging(Group CA) was increased remarkably compared to the asthma group(Group A1)[(1.125±0.254)μg/mL vs(0.825±0.173)μg/mL,P lt;0.01].The nonspecific airway resistances induced by different concentration of acetylcholine in Group CA [(0.997±0.196)cm H2O•mL-1•s-1,(1.123±0.142)cm H2O•mL-1•s-1,(1.130±0.197)cm H2O•mL-1•s-1]were increased significantly compared to Group A1 [(0.655±0.089)cm H2O•mL-1•s-1,(0.687±0.048)cm H2O•mL-1•s-1,(0.821±0.043)cm H2O•mL-1•s-1](all P lt;0.05).In Group Ⅱ,however,the above parameters in the asthma group treated with A. fumigatus spores after OVA challenging(Group AC) were not dramatically increased compared with the asthma group(Group A2)(all P gt;0.05).The differences in the total and differential cell counts in BALF in Group CA were not remarkable compared to other subgroups in Group Ⅰ(all P gt;0.05).But the BALF neutrophil count in Group AC was increased obviously compared to Group A2 [(2.488±0.420)×106 vs (0.936±0.459)×106,P lt;0.05].Conclusion These data indicate that exposure to A. fumigatus spores before challenging causes aggravated epithelial damage and increased airway resistance in an asthma rat model.
Citation: WANG Yan,LONG Fei,QI Huihui,JIN Xianqiao. Effects of Aspergillus fumigatus spores on airway inflammation and airway responsiveness on asthmatic rat model. Chinese Journal of Respiratory and Critical Care Medicine, 2007, 6(3): 185-190. doi: Copy