Induction of hepcidin expression in response to acute iron loading does not result from the increase of BMP6 mRNA expression. Weanling male rats were first fed a control diet (50 mg Fe/kg diet, group control) or were pair-fed an ID diet (< 2 mg Fe/kg diet, group ID) for 3 days. Animals in each category were then divided into 3 groups. One group (−) was euthanized immediately, whereas the other 2 groups were injected intraperitoneally with either FAC in phosphate-buffered saline at approximately 2.5 mg iron per 100 g of body weight or pair-injected with an equal amount of AC. The last 2 groups of animals were euthanized for analysis after 3 hours. (A) Serum Tf saturation in control and ID animals before injection (−) or after injection with AC or FAC. (B) qRT-PCR analysis of hepatic hepcidin mRNA in control and ID animals before injection (−) or after injection with AC or FAC. Liver tissues were collected from the same animals as described previously in panel A. Results are expressed as the amounts relative to β-actin. (C) qRT-PCR analysis of hepatic BMP6 mRNA in control and ID animals before injection (−) or after injection with AC or FAC. Liver tissues were collected from the same animals as described previously in panel A. Results are expressed as the amounts relative to β-actin. There are 4 animals per group. For all results shown previously, the mean values and the SD for each group are presented. The one-way analysis of variance and Tukey post test were used to compare the difference between groups. *P < .05; **P < .001; ***P < .001.