Bombesin is a 14-amino acid peptide originally isolated from the skin of the European fire-bellied toad (Bombina bombina). It has two known homologs in mammals called neuromedin B and gastrin-releasing peptide.
Bombesin receptor antagonist that inhibits bombesin binding to rat brain with an IC50 value of 2 μM. Inhibits amylase release in vitro (IC50 = 4 μM) and attenuates bombesin-mediated suppression of food intake in vivo.