RESUMEN
Objective:To observe the effect of high zinc concentrations on contents of iron and zinc and expression of their regulating mRNA in Caco-2 cells.Methods: Caco-2 cells were used as model of human small intestinal enterocytes and were treated for 24 h with 4,50,100 and 200 ?mol/L of zinc.The zinc and iron contents were determined by atom absorption spectrophotography and the expression of DMT1,IREG1,ZnT1 and hZIP4 mRNA were determined by RT-PCR(the level of GAPDH was taken as internal control).Results: The zinc content in Caco-2 cells was increased 24 h after treatment with zinc,and reached the peak when exposed to 50 ?mol/L zinc.The iron content decreased with the increase of zinc concentration.Zinc supplement increased the expressions of DMT1,IREG1 and ZnT1 mRNA but decreased the expression of hZIP4 mRNA.Conclusion: It is suggested that zinc supplement can increase the contents of zinc but decrease the contents of iron in Caco-2 cells.There may be interactions between iron and zinc in the intestinal lumen.