Establishment of neutrophilic asthma model in guinea pigs

Objective To establish the neutrophilic asthma model in guinea pigs.Methods Forty adult male guinea pigs were ramdomly divided into five groups:control group (group A),eosinophilic asthma group (group B),neutrophilic asthma group (group C),eosinophilic asthma treatment group (group D),neutrophilic asthma treatment group (group E).The guinea pigs in group B and C were sensitized with ovalbumin(OVA) and Freund's complete adjuvant (FCA) together or OVA alone,then were continuously stimulated with OVA atomization inhalation until appearing asthma symptom to establish neutrophilic asthma model or eosinophilic asthma model.The guinea pigs of the two treatment groups were intraperitoneal injected with dexamethasone before challenge.The change of behavior and bronchial lung tissue pathology of guinea pigs after challenge were observed.The total number of cell and differential cell counts in brochial alveolar lavage fiuid (BALF) and blood,airway resistance were detected.Results The guinea pigs of group B and C shown typical symptoms of asthma,and their airway resistance after different concentrations of methacholine challenge were significantly higher than group A (P0.05).The total cell counts and percentage of eosinophil (EOS%) in BALF and blood of group B were significantly higher than group A (P0.05).The total number of cells and the proportion of neutrophil of BALF and blood in group C were significantly higher than group A (P0.05).The percentage of neutrophil of BALF and blood in group C were significantly higher compared with which in group B (P0.05).Except for the percentage of neutrophil of blood in group B and D,the other indicators of the group D and E which were mentioned above decreased significantly compared with group B and C respectively (P0.05).The pathological study showed that luminal narrowing of bronchus, glandular hypertrophy and inflammatory cells infiltration in the group B and C,of which group B was mainly infiltrated with eosinophil and group C was primarily infiltrated with neutrophil.Compared with group B and C the pathological change of Guinea Pigs in group D and E was improved obviously.Conclusions We have successfully established a model of meutrophilic asthma in guinea pigs.