Eosinophil accumulation and activation in antigen-induced late asthmatic response in guinea pigs.

The purpose of this study was to investigate the participation of airway eosinophils in the antigen-induced late asthmatic response (LAR) and increased airway responsiveness in the guinea pig model of asthma. After antigen challenge, guinea pigs sensitized with aerosolized ovalbumin showed a late-phase decrease in specific airway conductance, which was accompanied by airway hyperresponsiveness to histamine, eosinophilia in the bronchoalveolar lavage fluid (BALF), decreased BALF eosinophil density, and increased generation of superoxide anions from purified BALF eosinophils. We demonstrated an association of the LAR with eosinophil accumulation and activation in the airway.