N-isobutyryl-His-Trp-Ala-Val-D-Ala-His-Leu-NHMe (ICI 216140) a potent in vivo antaconist analogue of bombesin/gastrin releasing peptide (BN/GRP) derived from the C-terminal sequence lacking the final methionine residue

Life Sci. 1989;45(17):1521-7. doi: 10.1016/0024-3205(89)90417-7.


The GRP receptor mediated growth response in Swiss 3T3 cells has been used to identify BN/GRP antagonists. Analysis of bombesin antagonism by substance P analogues and by truncated GRP analogues revealed that deletion of the C-terminal methionine residue was important for antagonism. Des-Met analogues showing potent antagonist activity in the in vitro 3T3 system (IC50 approximately 2nM) were synthesized. Further structural modification of these peptides led to the identification of (CH3)2CHCO-His-Trp-Ala-Val-D-Ala-His-Leu-NHCH3 (ICI 216140) which reduced bombesin-stimulated rat pancreatic amylase secretion to basal levels when administered subcutaneously at 2.0 mg per kg.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding, Competitive
  • Bombesin / antagonists & inhibitors*
  • Bombesin / metabolism
  • Cell Division / drug effects
  • Cells, Cultured
  • Gastrin-Releasing Peptide
  • Indicators and Reagents
  • Kinetics
  • Mice
  • Molecular Sequence Data
  • Oligopeptides / chemical synthesis
  • Oligopeptides / pharmacology*
  • Peptides / antagonists & inhibitors*
  • Receptors, Bombesin
  • Receptors, Neurotransmitter / metabolism*
  • Structure-Activity Relationship


  • Indicators and Reagents
  • Oligopeptides
  • Peptides
  • Receptors, Bombesin
  • Receptors, Neurotransmitter
  • ICI 216140
  • Gastrin-Releasing Peptide
  • Bombesin