The Comparation of Intraperitoneal Injection and Nasal-only Delivery Allergic Rhinitis Model Challenged With Different Allergen Concentration.

Background Predominantly, 2 animal models are used for allergic rhinitis (AR), which are established by intraperitoneal (IP) injection plus local challenge and nasal-only delivery. The differences between these 2 models are not fully understood. Moreover, dose-response relationship to allergens remains unclear. Methods In this study, mice were sensitized by nasal drops (without adjuvant, once daily for 9 weeks) to set up a nasal-only delivery AR model. Five different doses of ovalbumin (OVA) nasal drops were served to explore the dose-response to allergens. Allergic symptoms, serum antibodies (IgE, IgG2a, and IgG1), spleen supernatant and nasal lavage fluid (NALF) cytokines (IL-4, IL-5, and IFN-r), and infiltrated eosinophils of the nasal mucosa were observed. Results The allergic symptoms, serum antibodies, cytokines, and infiltrated eosinophils were significantly higher in the high OVA concentration compared with those of the control group. Different OVA concentrations associated with the severity of allergy. Within a certain concentration range, OVA concentration positively related to the severity of symptoms, IgE antibody level, and Th2 bias. Meanwhile, serum antibodies (IgE and IgG1) and cytokines (IL-4, IL-5 in spleen and IL-4 in NALF) were significantly higher in the classical IP injection group than in the nasal drip groups. Conclusion The IP injection model and the nasal-only delivery model are 2 typical models for AR that causes a different immune response. A positive dose-response relationship in the nasal-only delivery model is observed from 25 mg/mL to 0.025 mg/mL.