Histological aspects of the pulmonary territory as seen in an experimentally ovalbumin induced inflammation in guinea pigs.

The microscopic morphology of the respiratory territory was investigated on sections of pulmonary tissue and bronchioalveolar lavage liquid (BAL) that were stained with Giemsa, PAS and trichrome solutions. As a result of the induced pathological conditions, the following histological images were encountered: normal histological aspect of the bronchoalveolar territory was seen in the groups nebulized with 0.9% NaCl or sensitized after i.p. administration of ovalbumin (OA); macrophage cells influx in both tissue samples and BAL in animals nebulized with OA; after sensitization with OA followed by nebulization with OA, the same sequence of events as in atopical asthma was reproduced, including loss of epithelial structure and the appearance of mast cells and basophils in the alveolar territory. Hydrocortisone hemisuccinate, used to treat asthma attacks, causes a similar histological aspect as in the untreated group. Cells with intact basophilic granules were seen in the hypersensitized group under ketotiphen protection.