Objective: To evaluate the correlation between upper and lower respiratory inflammation.
Methods: Thirty rats were randomly divided into allergic rhinitis group (AR), asthma group (AS), and control group (Con). The pulmonary function was measured by pulmonary function instrument of animal model, the infiltration of eosinophils and mast cells was detected by hematotoxylin-eosin staining (HE staining) and toluidine blue staining respectively, the expression of VCAM-I and IL-13 was examined by immunohistochemistry. ELISA was used to measure the concentration of IL-5 in the peripheral serum.
Results: The numbers of eosinophils and mast cells in nasal mucosa and lung tissue of AR were both significantly higher than those of Con, and similar results were observed between AS and Con. The forced expiratory volume in 0.3 second (FEV0.3)/forced vital capacity (FVC) of AR and AS was both significantly lower than that of Con. The numbers of VCAM-I and IL-13 positive vessels in lung tissue of AR were both significantly higher than those of Con, and similar results were observed between AS and Con. The concentration of IL-5 in the serum of AR and AS was both significantly higher than that of Con. The concentration of IL-5 in serum was positively correlated with the number of eosinophils in peripheral blood of AR and AS.
Conclusion: The inflammation is similar between AR and AS, and repeatedly challenge upper respiratory tract can impact on lower respiratory response.