Whole-body distribution of americium in rats for different pathways of intake

Abstract

Purpose: To compare data on the whole-body distribution of americium-241 (²⁴¹Am) in rats following intravenous injection (IV), inhalation, and wound (intramuscular injection, IM).

Material and methods: Following exposure, each rat was placed in an individual metabolism cages for the duration of the study, 28 days (d). Urine and feces were collected daily. Tissues and organs were collected and measured.

Results: Liver and skeleton were the main sites of deposition for all routes of exposure but the content differed substantially. By 28 d, ²⁴¹Am content in liver was similar for IV and IM administrations (12 ± 4% and 14 ± 5%, respectively), which was 3-fold higher compared to inhalation. Americium-241 content in skeleton was 27% by the end of the IV study; which was 50% higher compared to the IM study and 6-fold higher compared to inhalation. The cumulative excretion in 28 d was 54% for IV (44% by feces and 10% by urine); 38% for IM (34% by feces and 4% by urine); and 84% for inhalation (83% by feces and 1% by urine).

Conclusion: Unperturbed rat models for the three routes of administration are the baseline for evaluating the efficacy of chelating agents.

Keywords::

• Americium biokinetics
• inhalation
• contaminated wound
• rats

Acknowledgements

The work described here is being supported by the U.S. National Institute of Allergy and Infectious Diseases, NIH, under contract HHSN272201000046C, through a subcontract with the University of Maryland Center Against Radiological Threats (MCART).

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.