ABSTRACT
UNLABELLED: 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.
