Up-regulation of antigens on alveolar macrophages in quartz exposed rats.

We have analysed the expression of the OX-6 and OX-42 antigens on alveolar macrophages in rats after intratracheal exposure to quartz. Eight female Sprague Dawley rats were included in the study. Four were exposed to physiological saline and four to quartz dust. The rats were sacrificed after 58 +/- 2 weeks and alveolar macrophages were harvested and analysed by flow cytometry. We found a significant higher amount of both antigens on alveolar macrophages harvested from quartz exposed rats. However, we did not find any significant difference in the percentage positive labeled cells between the two groups. We conclude that quartz dust induces up-regulation of functional receptors on alveolar macrophages in rats and that quantitative analysis of these receptors may serve as inflammatory markers in the bronchoalveolar space.