Leukocyte migration toward the alveoli]

Migratory processes of leukocytes toward alveolus have been studied after intratracheal injection of aluminium or beryllium hydroxide. Migrating cells could only be observed during the first three days following the injection. Three migrating processes were pointed out and especially an emperipolesis phenomenon. This morphological observation and cytokinetic study of septal cells, exclude the existence of a precursor septal pool involved in a maturation process of alveolar macrophages.