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.
Litorin, an amphibian bombesin peptide derivative, is found to suppress the nutriment, to stimulate the contraction of smooth muscle, to stimulate gastrin, gastric acid, and pancreatic secretion.