RECHERCHES INFRA-STRUCTURALES SUR L'ÉVOLUTION DES MACROPHAGES ALVÉOLAIRES ET LEURS RÉACTIONS AUX POUSSIÈRES MINÉRALES

Abstract The electron microscopic examination of normal alveolar macrophages, harvested by washing out the lungs, reveals common features which are those of histiocytic cells, differing from other pulmonary parietal lining cells, and features peculiar to the species investigated (cat, rabbit, guinea pig, man), concerning the lysosomic cytoplasmic inclusions. The investigation of a great number of cells shows the possible evolution from a small non phagocytic lymphocyte-shaped cell, identical in all species, to the well-known large alveolar macrophage. As a rule phagocytosis is related to lysosomic structures and clears most of them away from the cytoplasm. The particles are usually surrounded by a cyto-membrane. Few cytological alterations after phagocytosis are observed. The presence of ingested particles causes iron to accumulate.