Whole-body distribution of plutonium in rats for different routes of exposure

To compare data on the whole-body distribution of plutonium-239 ((239)Pu(4+)) in rats following a single administration by intravenous injection (IV), inhalation, and wound (intramuscular injection [IM]).

For each route of administration there were eight experimental groups, determined by the time of sacrifice following (239)Pu(4+) administration. The groups consisted of three male and three female F344 rats. Rats were placed in metabolism cages where urine and feces were collected daily. At sacrifice, rats underwent necropsy with tissues collected for radioactivity measurement.

Skeleton had the largest fraction of (239)Pu(4+); for IV, 50% by 1 hour (h) post exposure, and for wound 40% by 6 days (d) post exposure; both routes followed the same retention pattern; however, for inhalation 0.4% of the activity was observed at the early time-points which slowly increased with time and by 28 d, 1% remained. Liver retained the second highest content. Following IV, 20% was observed at 2 d and for IM, 6% at 4 d. Following inhalation exposure, 0.5% was found in liver by the conclusion of the study, 28 d.

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