[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)