Interactions between ethylenediaminetetraacetic acid (EDTA) and iron absorption pathways, in the Caco-2 model.
EDTA is a well known enhancer of iron absorption; however, the precise way of absorption of iron ingested in presence of EDTA is not known; some data suggest it could use a passive, non regulated paracellular way. Iron (sulphate or gluconate) absorption by Caco-2 cells was assessed in presence of EDTA. EDTA did not change the apical uptake of iron; transport in the basal chamber increased by 98% for FeSO4 and 95% for Fe gluconate. By contrast, intracellular storage decreased by 31% for FeSO4 and 64% for Fe gluconate. In addition EDTA induced a significant increase of permeability of the cell monolayer assessed by a decrease of transepithelial electrical resistance: 314+/-34 Omegacm(-2) to 235+/-57 Omegacm(-2) for sulphate, 414+/-33 Omegacm(-2) to 223+/-36 Omegacm(-2) for gluconate; iron free control: 410+/-10 Omegacm(-2).


CONCLUSIONS
These results suggest that in presence of EDTA iron absorption occurs mainly by the paracellular instead of the regulated cellular way, that could potentially enhance its toxicity.
Kibangou
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IB
Laboratoire de Physiologie Digestive et Nutritionnelle, CHU de Caen, 14033, Caen, France.
Bureau
F
F
Allouche
S
S
Arhan
P
P
Bouglé
D
D
D001682:Biological Availability; D018938:Caco-2 Cells; D004492:Edetic Acid / Q000494:pharmacology*; D005296:Ferrous Compounds / Q000378:metabolism / Q000493:pharmacokinetics; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects* / Q000502:physiology*; D007501:Iron / Q000493:pharmacokinetics*
D005296:Ferrous Compounds; C020748:ferrous sulfate; D004492:Edetic Acid; D007501:Iron; C011819:ferrous gluconate