PHZ-induced hemolysis results in iron accumulation in spleen and liver of mice lacking Fpn1 in their macrophages. Sex-matched 2-month-old Fpn1^flox/flox and Fpn1^LysM/LysM mice were injected intraperitoneally with PHZ at 40 μg per gram of body weight on each of 2 consecutive days. Animals were killed on days 4, 8, or 12, and tissue and blood were harvested for analysis. The first day of PHZ injection was designated as day 0. (A) Spleen nonheme iron concentrations. (B) Total nonheme iron content of the spleen. (C) Liver nonheme iron concentrations. (D) Relative Hamp1 mRNA levels in liver. (E) Heme concentrations in the spleen. (F) Relative Flvcr mRNA levels in the spleen of Fpn1^flox/flox and Fpn1^LysM/LysM mice were measured by quantitative RT-PCR. Results were normalized to the internal control β-actin and presented as relative expression level calculated by the 2^ΔΔC_t method; data are mean ± SEM; n = 6 per group (3 male, 3 female). *P < .05. †P < .001.