[Tyr⁴]-Bombesin

Bombesin is a 14 amino acid peptide originally isolated from the skin of a frog. Bombesin has two known homologues in mammals called neuromedin B and gastrin releasing peptide. Bombesin works on the gastrointestinal tract neuroendocrine hormone and bombesin stimulates gastrin release from G cells. Bombesin activates three different G-protein coupled receptors known as BBR1 2 and 3. Bombesin also activates these receptors in the brain. Together with cholecystokinin bombesin is the second major source of negative feedback signals that stop eating behavior.