DISSOLUTION OF MAN-MADE VITREOUS FIBERS IN RAT ALVEOLAR MACROPHAGE CULTURE AND GAMBLES SALINE SOLUTION - INFLUENCE OF DIFFERENT MEDIA AND CHEMICAL-COMPOSITION OF THE FIBERS

The effect of different chemical compositions of man-made Vitreous fib ers (MMVF) on their dissolution by alveolar macrophages (AM) in cultur e and in Gamble's solution was studied. The fibers were exposed to cul tured rat AMs, culture medium alone; or Gamble's saline solution for 2 , 4, or 8 days. The dissolution of the fibers was studied by measuring the amount of silicon (Si), iron (Fe), and aluminium (Al) in each med ium. The AMs in culture dissolved Fe and Ai from the fibers but the di ssolution of Si was more marked in the cell culture medium without cel ls and in the Gamble's solution. The dissolution of Si, Fe, and Al was different for different fibers, and increased as a function of time. The Fe and Al content of the fibers correlated negatively with the dis solution of Si by AMs from the MMVF, i.e., when the content of Fe and Al of the fibers increased the dissolution of Si decreased. These resu lts suggest that the chemical composition of MMVFs has a marked effect on their dissolution. AMs seem to affect the dissolution of Fe and Al from the fibers. This suggests that in vitro models with cells in the media rather than only culture media or saline solutions would be pre ferable in dissolution studies of MMVFs.