Iron dextran injection facilitates iron export in Tet1^−/− macrophages and increases FPN protein levels. (A) Hepatic and splenic nonheme iron concentration was measured in Tet1^+/+ and Tet1^−/− mice 7 days after a single intraperitoneal injection of iron dextran (250 µg/g body weight) (n = 6 mice per group). (B) RT-PCR analysis of hepatic Hamp1 mRNA in untreated and iron dextran‒injected Tet1^+/+ and Tet1^−/− mice (n = 4-6 mice per group). (C-D) RT-PCR analysis of Fpn, Dmt1, Tfr1, and Fth mRNA in the liver and spleen of iron dextran‒injected Tet1^+/+ and Tet1^−/− mice (n = 6-7 mice per group). (E) Western blot analysis and quantification of FPN protein measured in iron dextran‒injected Tet1^+/+ and Tet1^−/− mice (n = 7 mice per group). (F) Perls’ Prussian blue staining of iron and FPN immunohistochemical staining and (G) quantification of spleen sections obtained from Tet1^+/+ and Tet1^−/− mice 3 and 7 days after iron dextran injection (n = 4 mice per group). (H) Western blot analysis and quantification of FPN protein measured in the indicated BMDMs treated as indicated (n = 5 mice per group). Scale bars, 100 μm (F-G). *P < .05 and **P < .01 (Student t test).