EFFICACY OF 3,4,3-LIHOPO FOR REDUCING THE RETENTION OF PU-238 IN RAT AFTER INHALATION OF THE TRIBUTYL-PHOSPHATE COMPLEX

The efficacy of 3,4,3-LIHOPO, a siderophore analogue, has been tested for removing Pu-238 from rat after inhalation of plutonium as the tri- N-butylphosphate (TBP) complex. The amounts of Pu retained in the lung of untreated rat, 7 days after exposure ranged from 0.86 to 37 kBq. T he results have been compared with DTPA, the current therapy of choice for man. The ligand 3,4,3-LIHOPO was more effective than DTPA for rem oving Pu from the body when repeated treatment began 1 h after inhalat ion. This observation was independent of the mass of Pu deposited in t he lungs. The efficacy of 3,4,3-LIHOPO was mainly due to the decrease of Pu retention in lung, 1.5 times less than after DTPA administration ; in liver and skeleton, retention was about four times less. Seven da ys after internal contamination, < 10% of the activity was found in or gans other than lung when rat was treated with 3,4,3-LIHOPO. As this l igand showed an apparent lack of irreversible toxicity, it is likely t o be of interest in the development of new decorporation treatments af ter inhalation of Pu as a TBP complex.