Pulmonary cellular and antibody response to trimellitic anhydride inhalation

Trimellitic anhydride (TMA) causes immunologically mediated lung disease in humans and rats. The purpose of this study was to determine the numbers and functional capacity of pulmonary free cells and to define the nature of TMA-specific antibody in rats exposed to low concentrations of TMA. Groups of Sprague-Dawley rats were exposed to 0, 2, 20, and 60 mu g/m super(3) of TMA 6 h/d, 5 d/wk for 2 wk. The numbers and types of cells, ectoenzyme and lysozyme activity, in vitro phagocytosis by pulmonary free cells, and serum lavage fluid antibody levels were determined. The total number of cells present in lavage fluid and protein content increased in a dose-related manner. There was a shift of differential cell counts toward neutrophils and lymphocytes. Alveolar macrophages were not adversely affected.