An activating and cytotoxic effect of asbestos on polymorphonuclear leukocytes.

Chrysotile asbestos induces extensive enzyme release from polymorphonuclear leukocytes (PMNs). The release of the cytoplasmic enzyme lactate dehydrogenase implies membrane damage and cytotoxicity. In the presence of extracellular Ca2+ asbestos exerts an activating effect, evident from the release of granule-associated enzymes by exocytosis. Both the cytotoxic and activating effect of asbestos may contribute to asbestos-induced tissue damage.