Phagocytosis of inhaled plutonium oxide-239pu particles by pulmonary macrophages.

Pulmonary macrophages and plutonium particles were removed by washing the lungs of rats that had inhaled plutonium oxide-(239)Pu. A significant amount of plutonium was found in multiple washings of the same lung. The removal of toxic particles by washing is of potential therapeutic value. Particles were phagocytized by macrophages during the first 3 hours and retained within these cells for up to 25 days. Nearly all particles in washings were found in macrophages after the second day. The percent of macrophages with engulfed particles increased with increasing amounts of plutonium deposited in the lungs. The ability of pulmonary macrophages to rapidly phagocytize and retain plutonium particles deposited in the lungs has been shown.