%0 Journal Article %T Omeprazole decreases magnesium transport across Caco-2 monolayers %A Narongrit Thongon %A Nateetip Krishnamra %J World Journal of Gastroenterology %D 2011 %I Baishideng Publishing Group Co. Limited %X AIM: To elucidate the effect and underlying mechanisms of omeprazole action on Mg2+ transport across the intestinal epithelium.METHODS: Caco-2 monolayers were cultured in various dose omeprazole-containing media for 14 or 21 d before being inserted into a modified Ussing chamber apparatus to investigate the bi-directional Mg2+ transport and electrical parameters. Paracellular permeability of the monolayer was also observed by the dilution potential technique and a cation permeability study. An Arrhenius plot was performed to elucidate the activation energy of passive Mg2+ transport across the Caco-2 monolayers.RESULTS: Both apical to basolateral and basolateral to apical passive Mg2+ fluxes of omeprazole-treated epithelium were decreased in a dose- and time-dependent manner. Omeprazole also decreased the paracellular cation selectivity and changed the paracellular selective permeability profile of Caco-2 epithelium to Li+, Na+, K+, Rb+, and Cs+ from series VII to series VI of the Eisenman sequence. The Arrhenius plot revealed the higher activation energy for passive Mg2+ transport in omeprazole-treated epithelium than that of control epithelium, indicating that omeprazole affected the paracellular channel of Caco-2 epithelium in such a way that Mg2+ movement was impeded.CONCLUSION: Omeprazole decreased paracellular cation permeability and increased the activation energy for passive Mg2+ transport of Caco-2 monolayers that led to the suppression of passive Mg2+ absorption. %K Magnesium %K Paracellular %K Proton pump inhibitor %K Transepithelial %K Tight junction %U http://www.wjgnet.com/1007-9327/full/v17/i12/1574.htm