Suppression of hepcidin mRNA in response to acute iron deprivation does not result from the transcriptional regulation of BMP6 and TMPRSS6 gene expression. (A) Serum Tf saturation in rats at day 0 and in rats fed either a control diet (white bar) or an ID diet (striped bar) for 1, 2, and 3 days. (B) qRT-PCR analysis of hepcidin (hepc), BMP2 (B2), BMP4 (B4), BMP5 (B5), BMP6 (B6), and BMP9 (B9) mRNA in the liver tissues from animals fed a control diet at day 0 (white bar) and 3 days (striped bar). (C-E) qRT-PCR analysis of hepcidin (hepc), TfR1, BMP2 (B2), BMP4 (B4), BMP5 (B5), BMP6 (B6), BMP9 (B9), and TMPRSS6 (TM6) mRNA in the liver tissues from rats fed either a control diet (□) or an ID diet (▨) for 1 day (C), 2 days (D), and 3 days (E). Results are expressed as the amounts relative to β-actin rather than GAPDH. Previous studies indicate that iron deficiency in rats increases GAPDH mRNA levels in the liver.²⁹  There are 5 animals per group for 0 day, 1 day, and 2 days, and 4 animals per group for 3 days. Tissues used in panel B were collected from a separate experiment. The mean values and the SD for each group are presented. The paired 2-tailed Student t test was used to evaluate the statistical significance for serum Tf saturation between the ID and corresponding control groups (A), as well as for the qRT-PCR results between day 0 and 3 day control groups (B) or between the ID and the corresponding control groups (C-E) for each gene of interest. * P < .05; **P < .01; ***P < .001.