Pharmacology and selectivity of various natural and synthetic bombesin related peptide agonists for human and rat bombesin receptors differs

- Pharmacology of 24 natural occurring/synthetic bombesin related agonists is compared for rat and human receptor bearing tissues.
- Binding affinities/potencies and efficacy of cell activation are determined for all peptides.
- 12 peptides had high affinity/potency for hGRP receptors, 8 for hNMB receptors, 1 for hBRS-3 receptor.
- There was no correlation between affinities for hGRP and rat GRP receptors, but there was with h- and rat NMB receptors.
- Results show the human and rat peptide agonist pharmacophore for human and rat GRP receptors differ markedly.
- Results also report a number of high affinity/potency agonists that may be useful for human studies.