title: Further studies on the influence of chemical form and dose on absorptions of Np, Pu, Am and Cm from the gastrointestinal tracts of adult and neonatal rodents.
abstract: Absorption of isotopes of the actinide elements Np, Pu, Am and Cm from various organic media and/or in combination with plant or animal ligands or tissue is compared with their absorption from an inorganic nitrate medium. Gastrointestinal (GI) transport of 238Pu, 239Pu, 241Am and 244Cm at high concentrations from citrate medium by adult rats and/or mice was higher than from nitric acid medium. Neptunium-237 absorption, however, was not increased by citrate; probably because its oxidation state was reduced from 237Np(V) to 237Np(IV) by the medium and by the GI content. Increasing the mass of the 237Np dose resulted in increased absorption. Neither incorporation of 238Pu in rat liver nor retention of 238Pu oxide in rat lungs enhanced absorption when those Pu-containing tissues were administered intragastrically to either adult or neonatal rats. Ranking of GI absorption of the various forms of Pu gavaged in these studies suggests that transport is in the order: Pu citrate greater than Pu phytate greater than biologically incorporated Pu greater than Pu nitrate.
authors.forename: M F
authors.initials: MF
authors.lastname: Sullivan
authors.forename: B M
authors.initials: BM
authors.lastname: Miller
authors.forename: P S
authors.initials: PS
authors.lastname: Ruemmler
authors.forename: J L
authors.initials: JL
authors.lastname: Ryan
mesh_terms: D008671:Actinoid Series Elements / Q000378:metabolism*; D000576:Americium / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn; D002951:Citrates / Q000378:metabolism; D019343:Citric Acid; D003476:Curium / Q000378:metabolism; D007408:Intestinal Absorption; D051379:Mice; D009405:Neptunium / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism; D009942:Organometallic Compounds; D010833:Phytic Acid / Q000378:metabolism; D011005:Plutonium / Q000378:metabolism; D051381:Rats; D014018:Tissue Distribution
chemical_list: D008671:Actinoid Series Elements; D002951:Citrates; D009566:Nitrates; D009942:Organometallic Compounds; C015459:plutonium nitrate; C041805:americium nitrate; D019343:Citric Acid; C029020:curium nitrate; C044522:neptunium nitrate; D011005:Plutonium; D009405:Neptunium; D010833:Phytic Acid; C036636:plutonium phytate; D003476:Curium; D000576:Americium