BBN is a natural linear amidated tetradecapeptide initially isolated from skin extracts of the European discoglossid frog Bombina bombina [32, 33]. Subsequently, a search for BBN counterparts in mammalian tissues was initiated. The neuromedins B (NMB) from the central nervous system and the gastrointestinal bombesin (so-called gastrin-releasing peptide, GRP) are the corresponding mammalian peptides. BN-like regulatory peptides exert a spectrum of physiological activities in the nervous system and the gut. These physiological activities are elicited after BBN like peptides bind to a group of three GPCRs in mammals and one GPCR in amphibians.