Biochemical changes in pulmonary cells following manganese oxide inhalation.

Inhalation of manganese oxide (Mn dose, 879.0 micrograms/m3) for 2 h reduced the total number of alveolar macrophages obtained by endotracheal lavage in pulmonary cell populations, slightly reduced cellular viability, and reduced both phagocytic capability and total protein in sonicated pulmonary cells. Increases in intracellular adenosine triphosphate and acid phosphatase specific activity were also exhibited by the pulmonary cells, but sonicated cells obtained from the exposed mice showed no change in lactic acid dehydrogenase specific activity. A slight increase in extracellular protein in the fluid phase of the lavage suspension was observed after manganese oxide exposure.