Efficacy of 3,4,3-LIHOPO for reducing the retention of 238Pu in rat after inhalation of the tributyl phosphate complex.

The efficacy of 3,4,3-LIHOPO, a siderophore analogue, has been tested for removing 238Pu 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. The 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 removing Pu from the body when repeated treatment began 1 h after inhalation. This observation was independent of the mass of Pu deposited in the 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 days after internal contamination, < 10% of the activity was found in organs other than lung when rat was treated with 3,4,3-LIHOPO. As this ligand showed an apparent lack of irreversible toxicity, it is likely to be of interest in the development of new decorporation treatments after inhalation of Pu as a TBP complex.