[Morphological changes in experimental lipid pneumonia (author's transl)].

The morphological changes were investigated by male rats after aerosol application of mineral oil above a period of three weeks. Beginning in the second week, there was a permanent increase of macrophages and foam cells in the alveolar septa and alveolar lumina in closed relation to the deposited mineral oil, visible by dark field illumination. The macrophages and foam cells showed a high activity of non-specific esterasis and acid phosphatasis whereas the activity of adenosine triphosphatasis clear decreased. In the third week the formation of focal granulomas started predominantly existing of histiocytes and only few foam cells.