Cytokine and free radical responses of alveolar macrophages in vitro to asbestos fibres

A method for culturing primary rat alveolar macrophages (AMs) for 14 days w as used to compare their responses to crocidolite and chrysotile asbestos f ibres, Exposure to crocidolite increased production of tumour necrosis fact or-alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta), whereas exposure t o chrysotile did not; neither fibre altered the production of interleukin 6 (IL-6), IL-1 beta production increased progressively, while TNF-alpha was fully elevated from day 1, Conversely, chrysotile, but not crocidolite, inc reased production of superoxide anion and nitric oxide (NO) radicals. These differential responses were only observed by extending the culture beyond the usual 1-3 days. (C) 2000 Academic Press.