Ultrastructural findings in the murine nonciliated bronchiolar cells (NCBC) after subacute inhalation of lead acetate

Air pollution is an important health problem in some countries. For Mexico City, repeatedly high levels of some metals including lead (Pb) have been r eported. Since there is no relevant information, we used an inhalation mode l to identify the possible lung cell damage after exposure of animals to Pb . We used thirty CD-1 male mice that were inhaling (for 1 hour) aerosolized lead acetate 0.1M, three times per week during two weeks. Mice were sacrif iced by cervical dislocation on days 1, 3, 5, 7, 10 and 15 after the last P b exposure. Their lungs were fixed by intratracheal instillation of glutara ldehyde. Lung tissue for morphological observation and metal concentration was sampled. In the exposed mice, on days 3 and 5 changes in the nonciliate d bronchiolar cells appeared. Whorl-like structures were present in the cel l apex. These structures compressed other organelles. On day 5 after the fi nal inhalation, the structures increased in size, and by day 10 they disapp eared. After the last inhalation, the metal concentration in the lung tissu e continuously decreased until day 7 when no more metal was detected. It wa s evident that the contact of the NCBC with Pb produces changes in the morp hology of these cells. The metal concentrations in the lung decreased when the exposure ended. This finding supports the assumption that Ph is not acc umulated in lung tissue. As a consequence, the cellular modifications decre ased and began their way to morphological recovery.