[Sar9, Met(O2)11]-Substance P (trifluoroacetate salt)

[Sar⁹, Met(O₂)¹¹]-Substance P (Sar-SP) is a peptide agonist of the neurokinin-1 (NK₁) receptor.¹ It is selective for NK₁ over NK₂ and NK₃ receptors. Sar-SP induces inositol phosphate formation in U373MG glioblastoma cells with an EC₅₀ value of 3.8 nM, an effect that can be blocked by the NK₁ receptor antagonist SR 140333.² It induces contractions in isolated human bronchi when used at concentrations of 3, 100, and 1,000 nM.³ Sar-SP (10, 25, 65, and 100 pmol/animal, i.c.v.) increases mean arterial pressure and heart rate in conscious rats.⁴

1.Regoli, D., Drapeau, G., Dion, S., et al.New selective agonists for neurokinin receptors: pharmacological tools for receptor characterizationTrends Pharmacol. Sci.9(8)290-295(1988) 2.Oury-Donat, F., Thurneyssen, L.O., Gauthier, T., et al.SR 1140333, a novel, selective, and potent nonpeptide antagonist of the NKl tachykinin receptor: Characterization on the U373MG cell lineJ. Neurochem.62(4)1399-1407(1994) 3.Barchasz, E., Naline, E., Molimard, M., et al.Interleukin-1β-induced hyperresponsiveness to Sar9,Met(O2)11 substance x 2 P in isolated human bronchiEur. J. Pharmacol.379(1)87-95(1999) 4.Cellier, E., Barbot, L., Iyengar, S., et al.Characterization of central and peripheral effects of septide with the use of five tachykinin NK1 receptor antagonists in the ratBr. J. Pharmacol.127(3)717-728(1999)