pPD and ferroxidase activities of mouse Hp are increased in iron deficiency. (A) In-gel pPD oxidase assay of extracts from sla, C57/BL/6J (Ctrl), iron-deficient (Fe–), or iron-replete (Fe+) mouse enterocyte protein extracts. (B) Relative pPD levels of sla, Ctrl, Fe–, and Fe+ extracts were quantified using National Institutes of Health (NIH) Image (NIH, Bethesda, MD), and densitometry values are expressed as relative densitometric units (RDUs). Data are means ± SD from 5 independent experiments. *Lanes are significantly different from each other and the control at P < .05. (C) In-tube pPD oxidase activity of replicate samples was measured by adding protein extracts to pPD oxidase assay solution for 30 minutes at 37° C and measuring the A530. Each bar represents the mean ± SD (n = 5). *Significant difference at P < .05. (D) Ferroxidase activity assay of 80 μg and 240 μg sla, C57/BL/6J (Ctrl), iron-deficient (Fe–), and iron-overload (Fe+) mouse enterocyte protein extracts. (E) Relative ferroxidase levels of sla, Ctrl, Fe–, and Fe+ extracts were quantified by using NIH Image and densitometry values expressed as relative densitometric units (RDUs). Data are means ± SD from 5 independent experiments. Lanes marked with different symbols are significantly different from each other and the control at P < .05.
