IC50: 0.5 nM for Y5
The actions of neuropeptide Y (NPY) are mediated by at least six G-protein coupled receptors denoted as Y1, Y2, Y3, Y4, Y5, and y6. Investigations using receptor selective ligands and receptor knock-out mice show that NPY effects on feeding are mediated by both Y1 and Y5 receptors. BWX 46 is a Y5 receptor selective agonist.
In vitro: BWX 46 selectively bound Y5 receptors, and inhibited cAMP synthesis by Y5 cells with potencies comparable to that of NPY. In addition, BWX 46 (10 μM) exhibited no significant effect on the cAMP synthesis by Y1, Y2, and Y4 cells. Thus, BWX 46 constitutes the lowest molecular weight Y5 selective agonist reported to date [1].
In vivo: Intrahypothalamic-injection of 30 and 40 μg of BWX 46 stimulated the food intake by rats in a gradual manner, reaching maximal level 8 h after injection. This response was similar to that exhibited by other Y5 selective agonists, but differed from that of NPY, which exhibited a rapider orexigenic stimulus within 1 h [1].
Clinical trial: Up to now, BWX 46 is still in the preclinical development stage.
Reference:
[1] Ambikaipakan Balasubramaniam, Sulaiman Sheriff, Weixu Zhai, William T. Chance. Bis(31/31’){[Cys31, Nva34]NPY(27–36)-NH2}: a neuropeptide Y (NPY) Y5 receptor selective agonist with a latent stimulatory effect on food intake in rats. Peptides 23 (2002) 1485–1490