BIBP3226 is a nonpeptide antagonist of neuropeptide Y (NPY) receptor Y₁(K_i= 1.1 nM).¹It is selective for Y₁over Y₂, Y₄, and Y₅receptors (K_is = >1,000 nM for all). It also binds to neuropeptide FF receptor 1 (NPFF1) and NPFF2 (K_is = 108 and 79 nM, respectively) and reverses NPFF-induced inhibition of forskolin-induced cAMP accumulation in CHO cells expressing human NPFF2 in a concentration-dependent manner.¹BIBP3226 inhibits NPY-induced increases in perfusion pressure in isolated rat kidney but not the NPY-induced twitch response in isolated rat vas deferens (IC₅₀s = 26 and >10,000 nM, respectively).²BIBP3226 inhibits NPY-induced increases in blood pressure in pithed rats (ED₅₀= 0.11 mg/kg).²It also inhibits NPFF-induced hypothermia in mice when administered intracerebroventricularly (i.c.v.) at a dose of 5 nmol.³

1.Mollereau, C., GouardÈres, C., Dumont, Y., et al.Agonist and antagonist activities on human NPFF2 receptors of the NPY ligands GR231118 and BIBP3226Br. J. Pharmacol.133(1)1-4(2001) 2.Rudolf, K., Eberlein, W., Engel, W., et al.The first highly potent and selective non-peptide neuropeptide Y Y1 receptor antagonist: BIBP3226Eur. J. Pharmacol.271(2-3)R11-R13(1994) 3.Fang, Q., Guo, J., He, F., et al.In vivo inhibition of neuropeptide FF agonism by BIBP3226, an NPY Y1 receptor antagonistPeptides27(9)2207-2213(2006)