Eosinophilic
bronchitis (EB) is a useful tool for studying
airway hyperresponsiveness (AHR), but an exact EB animal model is lacking. Our objective was to establish an EB mouse model using
ovalbumin (OVA). Mice were divided into
asthma,
normal saline (NS) control and three model groups.
Asthma mice were challenged intranasally with 200 μg OVA. Model groups were challenged with one of the three OVA doses (10, 20 or 100 μg), and NS control mice received
normal saline. Changes in lung resistance (R(L)), serum OVA-specific
immunoglobulin-E (
IgE) and differential inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were determined after exposure to increasing doses of
methacholine (MCh). Lung histological sections were examined for inflammatory infiltration. R(L) in the 10-μg OVA-challenged model group was not significantly different compared with the NS group at any MCh concentration but was significantly different compared with the
asthma group (P < 0.01). R(L) in the other two model groups was intermediate between the
asthma and NS groups. Serum OVA-specific
IgE and eosinophils in BALF were increased significantly in all model and
asthma groups compared with the NS group, but no significant differences were observed between model and
asthma groups. Inflammatory cells were seen around bronchioles and capillaries in model and
asthma groups but not the NS group. A mouse model of EB without AHR can be established by 10 μg OVA challenge and provides a useful tool for studying AHR mechanisms.