title: Iron absorption from concentrated hemoglobin hydrolysate by rat.
abstract: Although heme iron is highly bioavailable, the low iron content of hemoglobin prevents its use for dietary fortification; on the other hand, purified heme has low solubility and absorption rate. The present study was designed to assess the interactions between concentrated heme iron and peptides released during globin hydrolysis and cysteine and their relation with iron absorption. Hemoglobin was hydrolyzed by pepsin or subtilisin, and then, heme iron was concentrated by ultrafiltration. Iron absorption was studied in a Ussing chamber; gluconate was used as control. Iron uptake from nonconcentrated pepsin hydrolysate and gluconate was lower than from other groups. Cysteine significantly enhanced iron uptake except from the concentrated subtilisin hydrolysate. There was no significant difference between cysteine-supplemented groups. According to the different hydrolysis pathways of enzymes, it is assumed that the presence of hydrophobic peptides and the strength of heme-peptide interactions are both determining factors of heme iron absorption. These interactions occur mainly before iron uptake, as emphasized by the effect of cysteine.
authors.affiliation: Laboratoire de Physiologie Digestive et Nutritionnelle, CHU, F-14033 Caen, France.
authors.forename: Nikta
authors.initials: N
authors.lastname: Vaghefi
authors.forename: Fuzia
authors.initials: F
authors.lastname: Nedjaoum
authors.forename: Didier
authors.initials: D
authors.lastname: Guillochon
authors.forename: François
authors.initials: F
authors.lastname: Bureau
authors.forename: Pierre
authors.initials: P
authors.lastname: Arhan
authors.forename: Dominique
authors.initials: D
authors.lastname: Bouglé
mesh_terms: D000818:Animals; D003545:Cysteine / Q000494:pharmacology; D015194:Diffusion Chambers, Culture; D005260:Female; D006418:Heme / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism*; D006868:Hydrolysis; D007408:Intestinal Absorption / Q000187:drug effects; D007501:Iron / Q000493:pharmacokinetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility
chemical_list: D006454:Hemoglobins; D006418:Heme; D007501:Iron; D003545:Cysteine