Fig. 1

CNP agglomerates are engulfed by alveolar macrophages. The histological examination of hematoxylin and eosin stained lung sections (upper panel) reveals no detectable changes in the lung architecture, 24 h after sham and CNP instillation. A spotty accumulation of particle laden alveolar macrophages can be observed in the alveolar region of CNP treated lungs. Cytospin analysis of May Grunwald stained BAL cell (lower panel) underlines this finding and also indicates the inflammatory response by accumulation of neutrophilic granulocytes (black arrow). A magnification of particle laden macrophages, shown in the framed sections is illustrated at the upper (histology) and lower (BAL cells) right corner of the respective image