Effects of parenteral iron overload in mice. (A) Mice treated with iron had significantly higher serum iron levels, while mice treated with lipopolysaccharide (LPS) alone became hypoferremic (two-way ANOVA with Bonferroni post hoc tests performed on log10-transformed values; P values adjusted for all possible comparisons). (B) Iron and lipopolysaccharide independently induce hepcidin (Hamp) mRNA levels in the liver (two-way ANOVA, interaction between iron and lipopolysaccharide not significant, therefore only main effects reported). N = 7 to 9 mice/group for (A, B). (C, D) Iron injection increases intracellular labile iron in circulating neutrophils and monocytes. Both neutrophils (Ly6G-positive cells) and monocytes (CD11b-positive cells) from the iron-treated mice had lower calcein fluorescence intensities, consistent with higher intracellular iron levels. Representative histograms are from one vehicle-treated (Veh) and one iron-treated mouse. The dot plots show mean fluorescent intensities of 3 to 4 mice/group (unpaired t test). Int = interaction P value; PMN = polymorphonuclear leukocytes.
