Efficacy of 3,4,3-LIHOPO for reducing neptunium retention in the rat after simulated wound contamination

Abstract

Purpose: The ligand 3,4,3-Li(1,2-HOPO) was tested for Np removal after intramuscular injection of 237 Np nitrate in rats. Materials and methods: Two experiments were performed, one with simultaneous injection of neptunium and LIHOPO at dosages ranging from 3 to 200mumolkg -1 and the other with delayed administration of LIHOPO 30mumolkg -1 from 5min to 30min after Np injection. Results: The data obtained after simultaneous injections showed that the ligand dosage effectiveness was not linear and depended on the tissues being considered. For bones, the best results were obtained with 200 mumolkg -1 LIHOPO, where retention was reduced to 11% of controls. Maximum efficacies for removal in liver and kidney were obtained with 30mumol kg -1 LIHOPO, where retention was reduced to 39% and 1.6% of controls, respectively. At higher dosages, LIHOPO seemed to have a reverse effect on these tissues, demonstrated by a significant accumulation of the radionuclide. The delayed administration of LIHOPO dramatically decreased its efficacy. When administered 5min after Np, LIHOPO was still efficient (60%, 37%, 7% of controls in bone, liver, kidneys, respectively) but not when treatment was delayed to 30min. Conclusions: These results demonstrated that LIHOPO was able to complex Np at the wound site but not after translocation to blood.