Rabbit lung after inhalation of manganese chloride: a comparison with the effects of chlorides of nickel, cadmium, cobalt, and copper.

Rabbits were exposed to aerosols of MnCl2 (mass median aerodynamic diameter 1 micron) in metal concentrations of 1.1 and 3.9 mg/m3 for 4-6 weeks, 5 days/week, 6 h/day. The effects of alveolar type II cells, phospholipids, alveolar macrophages, and lung structure in general were compared with earlier reported effects of Ni2+, Cd2+, Cu2+, and Co2+. Except for a significant increase in the diameter of the alveolar macrophages after exposure to the higher Mn2+ concentration, no abnormalities were seen. The results of this and earlier studies indicate that these five metal ions have different, specific effects on the alveolar part of the lung.