Demonstration of the proopiomelanocortin signaling system in the primary immune organ of the quail.

There is growing evidence to suggest that proopiomelanocortin (POMC), a precursor of adrenocorticotropin and alpha-melanocyte-stimulating hormone (alpha-MSH), also exists in extrapituitary organs, including immune organs. We investigated the presence of the POMC signaling system in the avian-specific primary immune organ the bursa of Fabricius (BF) of the adult quail. Immunohistochemical staining revealed the presence of cells showing immunopositive reaction with anti-alpha-MSH antibody in the quail specimens.