Effect of hepcidin on iron absorption in Hfe KO mice. Wild-type (wt) or Hfe knockout (Hfe-KO) mice were injected with 0.15 M NaCl (sal) or hepcidin (50 μg single intraperitoneal injection) on each of 2 consecutive days, 24 hours before measuring iron absorption with tied-off duodenal segments. Data shown are mucosal retention (▪), transfer of radioiron to the carcass (▦), and total mucosal uptake of radioiron (□). Significance of effects was analyzed by ANOVA and is shown in Table 5. *P < .05, **P < .01 compared with mice of the same genotype injected with saline.