Phagocytosis of Inhaled Plutonium Oxide- ²³⁹ Pu Particles by Pulmonary Macrophages

Abstract

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.

Alterations in Macrophage Functions by Environmental Chemicals

“…Data indicate a positive correlation between the amount of particles cleared and the number of these phagocytic cells in the lung (18). A number of inhalable substances such as carbon (1,6,18,32), diesel exhaust (33), PbO (34), NiC12, NiO (35-37), CdCl2 (38), CO (39), Pb2O3 (8,40), cigarette smoke (24,(41)(42)(43), cotton dust (44), quartz (45) and other environmental substances (46,47) can promote the influx of macrophages into the pulmonary racemus. Little is known about the mechanisms of action that stimulate this migration or about the fate of these immigrant cells.…”

Removal of Inhaled Radioactive Particles by Lung Lavage - A Review

“…The removal of 239Pu02 particles by lavage from excised rat lungs was demonstrated in 1968 (Sa68) and reported again in 1969 (Sa69a; Sa69b). The first use of lavage to remove radioactive particles from lungs of living animals was reported in 1969 (Pf69a).…”

Electron Microscopic Radioautography: Identification of Origin of Synaptic Terminals in Normal Nervous Tissue

“…After the injection of tritiated amino acid into a specific neuronal site, the isotope is incorporated into protein within the neuronal cell body (2)(3)(4)(5). This protein then moves along the axons that originate from the neurons in the injected region, finally appearing in their terminal portions.…”

“…After vitreal injection of tritiated leucine, the label rapidly appears in retinal proteins (2,4,5). Scintillation counting (12) of the monkey visual system after injection with tritiated leucine indicated that subsequently some of this incorporated label moved along the optic nerve.…”