Some biochemical effects of asbestos on macrophages.

Abstract

The in vitro effects of chrysotile, crocidolite and amosite asbestos, and silica and rutile dust, on hamster peritoneal macrophages were assessed by estimating the release of acid phosphatase into the culture medium and by changes in the composition of phospholipids in the cells. Chrysotile was as toxic as silica, while crocidolite, amosite and the control dust, rutile were inert. The toxicity of chrysotile and silica is evidently due to the surface interaction of the dusts with phagosomal membranes, leading to the release of lytic enzymes from the damaged phagosomes into the cytoplasm. Considerable amounts of acid phosphatase were released into the medium 28 hours after the phagocytosis of both dusts, whereas very little was found when crocidolite, amosite and rutile were used. Further evidence of cytopathic effects was seen by changes in lipid components of cells which had ingested silica and chrysotile. A decrease in total lipid content and an increase in lysolecithin apparently indicate specific, secondary and toxic effects following the release of lysosomal enzymes.