title: Olfactory ferric and ferrous iron absorption in iron-deficient rats.
abstract: The absorption of metals from the nasal cavity to the blood and the brain initiates an important route of occupational exposures leading to health risks. Divalent metal transporter-1 (DMT1) plays a significant role in the absorption of intranasally instilled manganese, but whether iron uptake would be mediated by the same pathway is unknown. In iron-deficient rats, blood (59)Fe levels after intranasal administration of the radioisotope in the ferrous form were significantly higher than those observed for iron-sufficient control rats. Similar results were obtained when ferric iron was instilled intranasally, and blood levels of (59)Fe were even greater in the iron-deficient rats compared with the amount of ferrous iron absorbed. Experiments with Belgrade (b/b) rats showed that DMT1 deficiency limited ferric iron uptake from the nasal cavity to the blood compared with +/b controls matched for iron deficiency. These results indicate that olfactory uptake of ferric iron by iron-deficient rats involves DMT1. Western blot experiments confirmed that DMT1 levels are significantly higher in iron-deficient rats compared with iron-sufficient controls in olfactory tissue. Thus the molecular mechanism of olfactory iron absorption is regulated by body iron status and involves DMT1.
authors.affiliation: Department of Genetics and Complex Diseases, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: V M
authors.initials: VM
authors.lastname: Ruvin Kumara
authors.forename: Marianne
authors.initials: M
authors.lastname: Wessling-Resnick
mesh_terms: D000042:Absorption; D000281:Administration, Intranasal; D018798:Anemia, Iron-Deficiency / Q000378:metabolism*; D000818:Animals; D027682:Cation Transport Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005290:Ferric Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics*; D005296:Ferrous Compounds / Q000008:administration & dosage / Q000493:pharmacokinetics*; D017136:Ion Transport; D007501:Iron / Q000097:blood*; D007504:Iron Radioisotopes; D008297:Male; D009297:Nasal Mucosa / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D000099236:Solute Carrier Family 11, Member 2
chemical_list: D027682:Cation Transport Proteins; D005290:Ferric Compounds; D005296:Ferrous Compounds; D007501:Iron; D007504:Iron Radioisotopes; D000099236:Solute Carrier Family 11, Member 2