The effect of different mineral dusts on the mechanism of phagocytosis: A scanning electron microscope study

Alveolar macrophages from normal rats were incubated with crocidolite asbestos fibers and quartz particles in vitro. The early events in phagocytosis were studied sequentially. Differences were found in the way in which macrophages recognized, attached, and phagocytosed the two dusts. Phagocytosis of quartz was extremely rapid: The macrophages typically developed long tenuous filopodia. Crocidolite was phagocytosed more slowly: Many macrophages developed large flattened pseudopodia. These different phagocytic mechanisms may reflect the different biochemical and cytotoxic properties of the dusts. © 1978.