Respiratory mast cells and basophiloid cells. I. Evidence that they are secreted into the bronchial lumen, morphology, degranulation and histamine release.
Studies of secretions obtained from the bronchi of dogs and monkeys by bronchial lavage demonstrated the presence of two types of cells with granules having the staining characteristics of mast cells or basophils. Larger pleomorphic granular cells appear to be mast cells. Smaller, round cells resemble basophils but are termed `basophiloid' because their identity is not established. These two cell types were studied extensively in bronchial lavage preparations obtained from ragweed-allergic and normal dogs. The results demonstrate that there is a significant increase in the per cent of histamine release from these bronchial lavage cells after exposure to ragweed antigen when the cells were obtained from the bronchi of ragweed-sensitive dogs. This histamine release correlated with direct observation of the percentage of degranulation of the mast and basophiloid cells. These results show that viable, antigen-reactive cells are secreted into the lumen of the bronchi. They are significant as a source of cells for studies of IgE-mediated reactions and as cells which may be important in IgE-mediated respiratory responses.