Histopathological and Immunohistochemical Evaluation of Airways of Guinea Pigs Sensitized with Aerosolized Ovalbumin Inhalation

This study was conducted to examine the histopathological and immunohistochemical changes of airways in guinea pigs repeatedly sensitized with aerosolized ovalbumin (OA) administered via an ultrasonic nebulizer. After the 10th exposure with OA, the guinea pigs were fully sensitized and showed the anaphylaxical changes, such as hemorrhage, emphysema, bronchoconstriction, and peri-bronchial and/or peri-vascular edema in the lungs. Furthermore, the increment of TUNEL and PCNA positive cells were detected among the alveolar epithelial cells, and a gradual increase of lymphocytes and eosinophils were found in the submucosa of the trachea and bronchus. The pathogenesis of these lesions were not clear, but the morphological features recognized in this study were very similar to those of vascular leak syndrome induced by the administration of interleukin-2. (J Toxicol Pathol 1997 ; 10: 199～203)