Bombesin Receptor Antagonists Small Molecules and Peptides

Bombesin receptors are activated by the endogenous ligands gastrin-releasing peptide (GRP), neuromedin B (NMB) and GRP18-27 (neuromedin C). There are three subtypes of the bombesin receptor. BB₁ was previously known as the NMB receptor while BB₂ was previously known as the GRP receptor. BB₃ is designated an orphan receptor, however it has been shown to respond to NMB peptides, albeit at a lower potentcy than BB₁.

The receptors are G_q/11-coupled and are involved in the regulation of many biological functions including sensory transmission, thermoregulation, feeding and pituitary, gastric and pancreatic secretion. They may also be involved in tissue development, proliferation and differentiation.