Effects of copper and ceruloplasmin on iron transport in the Caco 2 cell intestinal model

Previous studies have implicated copper proteins, including ceruloplasmin, in intestinal iron transport. Polarized Caco2 cells with tight junctions were used to examine the possibilities that (a) ceruloplasmin promotes iron absorption by enhancing release at the basolateral cell surface and (b) copper deficiency reduces intestinal iron transport. Iron uptake and overall transport were followed for 90 min with 1 μM 59Fe(II) applied to the apical surface of Caco2 cell monolayers. Apotransferrin (38 μM) was in the basolateral chamber. Induction of iron deficiency with desferrioxamine (100 μM; 18 h) markedly increased uptake and overall transport of iron. Uptake increased from about 20% to about 65% of dose, and overall 59Fe transport from