Fasting and forskolin increases hepatic hepcidin gene expression and production in mice. (A) Wild-type (WT) mice were fed ad libitum (Fed) or fasted for 24 hr (Fast). Gene expressions were analyzed by qPCR using gene-specific primers. Expression levels of various proteins in liver tissue extracts were analyzed by immunoblotting using specific antibodies. (B) Expression profiles of predicted microRNAs (miR) in mouse livers. (C) Serum hepcidin and (D) iron contents in indicated mice groups. (E) Serum iron concentration after hepcidin-25 (Hepc25, 100 μg/kg) treatment for 12 h. (F) WT mice were injected intraperitoneally with forskolin (FSK, 5 mg/kg) and glucagon (GLU, 10 μg/kg) for 6 hr. qPCR experiments were then performed using various primers. (G) Serum levels of hepcidin and (H) iron at the indicated condition (n = 5 mice per group). *P < 0.05, **P < 0.01 vs. fed mice or untreated control mice.