The neuromedin B receptor antagonist, BIM-23127, is a potent antagonist at human and rat urotensin-II receptors

Br J Pharmacol. 2003 May;139(2):203-7. doi: 10.1038/sj.bjp.0705251.


The functional activity of the peptidic neuromedin B receptor antagonist BIM-23127 was investigated at recombinant and native urotensin-II receptors (UT receptors). Human urotensin-II (hU-II) promoted intracellular calcium mobilization in HEK293 cells expressing the human UT (hUT) or rat UT (rUT) receptors with pEC(50) values of 9.80+/-0.34 (n=6) and 9.06+/-0.32 (n=4), respectively. While BIM-23127 alone had no effect on calcium responses in either cell line, it was a potent and competitive antagonist at both hUT (pA(2)=7.54+/-0.14; n=3) and rUT (pA(2)=7.70+/-0.05; n=3) receptors. Furthermore, BIM-23127 reversed hU-II-induced contractile tone in the rat-isolated aorta with a pIC(50) of 6.66+/-0.04 (n=4). In conclusion, BIM- 23127 is the first hUT receptor antagonist identified to date and should not be considered as a selective neuromedin B receptor antagonist.

MeSH terms

  • Animals
  • Aorta, Thoracic / drug effects
  • Binding, Competitive
  • Calcium / metabolism
  • Cell Line
  • Dose-Response Relationship, Drug
  • Humans
  • In Vitro Techniques
  • Male
  • Peptides, Cyclic / pharmacology*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Bombesin / antagonists & inhibitors*
  • Receptors, G-Protein-Coupled / antagonists & inhibitors*
  • Urotensins / pharmacology


  • BIM 23127
  • Peptides, Cyclic
  • Receptors, Bombesin
  • Receptors, G-Protein-Coupled
  • UTS2R protein, human
  • Urotensins
  • Uts2r protein, rat
  • urotensin II
  • Calcium