The Effects Of DEP Inhalation On Asthmatic Reaction In Mice

Objective: To explore the effcets of DEP inhalation on asthmatic reaction inmice.Methods: C57BL/6 male mice were randomly divided into control group whichinhaled saline for 4 weeks, and experimental group which contained 4 smallgroups that inhaled DEP for 1, 2, 3 and 4 weeks respectively. Changes ofbronchial responsiveness were observed through the enhanced pause-2(Penh-2)by bronchial provocation test; differentia cell numbers were counted inbronchialveolar lavage fluid (BALF) by Giemsa staining; the pathologicalchanges of lung tissue were observed by HE and Masson-trichrome staining, andthe total levels of IgE in serum were determined by ELISA. The cytokineexpression of IFN-γ, IL-4, IL-5 in lung tissue were observed by reversetranscription polymerase chain reaction (RT-PCR).Results: No airway hyperresponsiveness(AHR) appeared after saline inhalationin control group, while AHR appeared after DEP inhalation which was related toinhalation time(r=-0.941, P＜0.01). In BALF of control groups, most commoncells were macrophage, When inhaled DEP for 1 week, a great deal of epitheliumwere observed, and different degree infiltration of inflammatory cells wereshowed since 2-week DEP inhalation, the lymphocyte were significantly higherthan that of control group(P＜0.01), eosinophil were significantly difference thanthat of control group(P＜0.01))after 4-week DEP inhalation. The epithelialshedding, infiltration of peribronchial inflammatory cells, and fibrosis on thebasement membrane sequentially were showed by lung pathology with theinhalation of DEP. The total level of IgE in serum of 3-week and 4-week DEPinhalation groups, which were significantly difference than control group(P＜0.01). RT-PCR result indicated that with inhalation time went by, theexpression of IFN-γwas decreased and then finally disappeared, there was noexpression of IL-4 in control group, but in experimental group, expression ofIL-4 begun after 1-week inhalation, expression of IL-5 increased gradually.Conclusions: The mice after DEP inhalation happened airway Hyperresponsiveness, inflammatory cells infiltration, total IgE level heighten, the express ofIL-4 and IL-5 in lung tissue was increased meanwhile IFN-γwas decreased. Inconclusion, the inflammatory changes of asthmatic reaction were induced by Th2lymphocyte.