RESPONSES OF ALVEOLAR MACROPHAGE TO METALLIC FUME

Alveolar macrophage was lavaged from lungs of rats exposed to inhalation of the particles of Sb, Pb, Cd, CaCO3 or poly vinyl chloride (PVC) and its number and 14C-leucine incorporating activity were studied. The number of free cell lavaged from the lung decreased remarkably by the exposure to Sb or Cd fume, while by the exposure to Pb fume, CaCO3 or PVC particles the number of lavaged cells did not change from that of control group breathing air in the exposure chamber. There was found a linear correlation 1 hr after inhalation between 14C-leucine in-corporation value for total cell and the number of lavaged cell in all the experi-mental groups except unrestrained (bred freely under normal condition) group and Sb group. That is, the incorporation value per cell in all the experimental groups except Sb group and unrestrained group was almost equal. In the case of Sb group and unrestained group the incorporation value per cell was lower than those of the other groups. Although the incorporation of 14C-leucine into cell in control group decreased by level of unrestrained group 21 hr after inhalation, in the Pb, CaCO3 or PVC group 14C-leucine incorporation into cell 21th hour did not change from that 1 hr after inhalation. 14C-leucine incorporation per cell in Sb group 21 hr after inhalation remarkably increased. This tendency was also seen in Cd group.The effects of the particles used in the inhalation experiment on the macrophage in vitro were also studied. The Sb fume was the most effective of all the samples and followed by Cd fume and then by Pb fume. The particles of CaCO3 or PVC were practically inert to the macrophage.