Hepcidin is a hormone, which belongs to the defensin family. These are cationic antimicrobial molecules and play an important role in systemic homeostasis of iron. Hepcidin is synthesized by hepatocytes and elated in the circulation where it targets the tissues and regulates the iron export function of ferroportin. Ferroportin is a ferrous iron permease.  

Identification of brain Hepcidin protein has been shown by implying methods like immune-chemistry and m RNA real-time PCR. Here, in situ hybridisation technique were also used to check the measurable transcription of Hepcidin gene in the Central Nervous System too. RT-PCR showed low concentration of Hepcidin m RNA in normal rat brain and in situ hybridization showed low to high levels of m RNA which were restricted to the choroid plexus and endothelium of blood vessels.

The protein immune-chemistry method showed high concentrations of Hepcidin protein in blood vessels, pericytes and in endothelium. Hepcidin was also present in the olfactory bulb, glial cells, dentate gyrus, and sub-ventricular zone. The co-localization of Hepcidin with ferroportin in the ependymal cells were consistent and managed the regulatory function in these sites. 

Thus, Hepcidin protein was expressed and detected in majority of the brain parenchyma. But the Hepcidin gene transcription was below the detection limits of in situ hybridization probes. This shows that part of Hepcidin is transcribed in some other part outside the brain.