Cytotoxicity, uptake and dissolution of 241AmO2 particles in dog alveolar macrophages in vitro.
Because alveolar macrophages play a role in the pulmonary clearance of inhaled particles, experiments were conducted to investigate the toxicity of 241AmO2 particles to alveolar macrophages and the role of these macrophages in the dissolution of 241AmO2 particles. Beagle dog pulmonary alveolar macrophages obtained by bronchopulmonary lavage were exposed in vitro to selected concentrations of 241AmO2. Macrophage viability determined by trypan-blue dye exclusion technique and the ability of the alveolar macrophages to phagocytose opsonized sheep red blood cells were the measures of 241AmO2 toxicity. The uptake of 241AmO2 particles was studied as a function of time. In addition, the dissolution of 241AmO2 by macrophages was determined for periods up to 72 h. After 20 h exposure to concentrations of 241Am higher than 4.63 kBq/ml, the phagocytic ability of macrophages was reduced, whereas no significant change in cell viability was observed at this concentration. Significant cell killing occurred at concentrations higher than 18.5 kBq/ml. After 72 h in the cultures, 10% of the 241AmO2 was dissolved by the alveolar macrophages. These findings imply that the inhalation of radioactive particles such as 241AmO2 particles might cause a reduction in the alveolar macrophage population in the lungs. In addition, the dissolution of 241AmO2 particles by alveolar macrophages might play a role in the short-term pulmonary clearance of inhaled 241AmO2 particles in the beagle dog.
Inhalation Toxicology Research Institute, Albuquerque, NM 87185.
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Taya
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Mewhinney
D000576:Americium / Q000493:pharmacokinetics / Q000633:toxicity*; D000818:Animals; D004285:Dogs; D005260:Female; D066298:In Vitro Techniques; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D008297:Male
C034018:americium oxide; D000576:Americium