title: Metabolism of plutonium introduced as Tri-N-Butylphosphate complex in the rat and removal attempts by DTPA.
abstract: The metabolism of plutonium introduced as the Pu-Tri-N-Butylphosphate complex (Pu-TBP) was studied in rats after inhalation, injection and ingestion. Early translocation and distribution of 239Pu in organs for 30-400 days after inhalation exposure are presented. The tracheobronchial clearance was impaired at early times, followed from about one week by clearance from the deep lung as characterized by a half time of 100 days. Skeleton was the main organ for deposition of the transferable fraction. The bone burden reached a plateau value of 10% of Initial Lung Burden (ILB) at 50 days after inhalation, while retention in liver reached 2% of ILB at 50 days and decreased to 0.3% by 1 yr after inhalation. Thirty days after intramuscular injection, translocated plutonium (15% of injected activity) resulted in a skeletal deposit that was 17.5 times higher than the deposit in the liver. By both routes, inhalation and intramuscular injection, 239Pu was transported in the blood as a Pu-transferrin complex. However, therapy with 30 mumol . kg-1 DTPA was ineffective. This result, together with the magnitude of the skeletal deposit observed, indicate that Pu-TBP follows a specific metabolic pathway that results in a Pu-transferrin complex that is more stable than the complexes described after Pu nitrate or citrate contamination. Lastly, absorption of Pu-TBP from the gut was poor, reaching 0.015% of the Pu given by gavage, a value not significantly different from the values assumed by ICRP 30 for class W compounds.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D005243:Feces / Q000032:analysis; D001239:Inhalation; D007273:Injections, Intramuscular; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008297:Male; D009942:Organometallic Compounds; D010755:Organophosphates / Q000008:administration & dosage*; D009943:Organophosphorus Compounds / Q000008:administration & dosage*; D004369:Pentetic Acid / Q000378:metabolism* / Q000627:therapeutic use; D011005:Plutonium / Q000008:administration & dosage* / Q000378:metabolism* / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D014168:Transferrin / Q000378:metabolism
chemical_list: D009942:Organometallic Compounds; D010755:Organophosphates; D009943:Organophosphorus Compounds; D014168:Transferrin; C038503:plutonium tri-n-butylphosphate complex; D011005:Plutonium; D004369:Pentetic Acid