GR231118

GR231118, an analogue of the C-terminus of neuropeptide Y, is a potent , competitive and relative seletive antagonist at human neuropeptide Y Y receptor with a pKi of 10.4. GR231118 a potent agonist at the human neuropeptide Y Y4 receptor (pEC50=8.6; pKi=9.6) and a weak agonist at the human and rat neuropeptide YY2 and Y5 receptors. GR231118 also has high affinity for the mouse neuropeptide Y Y6 receptor (pKi= 8.8)[1].

NPY Y₄ receptor

[1] E M Parker, et al. GR231118 (1229U91) and other analogues of the C-terminus of neuropeptide Y are potent neuropeptide Y Y1 receptor antagonists and neuropeptide Y Y4 receptor agonists. Eur J Pharmacol DOI:10.1016/s0014-2999(98)00171-x
[2] Y Dumont, et al. [(125)I]-GR231118: a high affinity radioligand to investigate neuropeptide Y Y(1) and Y(4) receptors. Br J Pharmacol.2000 Jan;129(1):37-46. DOI:10.1038/sj.bjp.0702983