Involvement of Y5 receptors in neuropeptide Y agonist-induced analgesic-like effect in the rat hot plate test

Neuropeptide Y (NPY) induces analgesic-like effects after central administration across diverse pain models in rodents. In spinal pain models, previous studies indicate a prominent role for Y1 receptors at mediating this effect of NPY. In supraspinal pain models like the hot plate test, the NPY receptors involved have not been thoroughly explored. By intracerebroventricular (i.c.v.) administration of selective NPY receptor ligands, the possible involvement of Y5 receptors in analgesic-like mechanisms was investigated using the hot plate test in rats. Both NPY and selective Y5 agonists induced analgesic-like effects as revealed by prolonged hot plate latencies. Further consistent with a role for Y5 receptors, pretreatment with a selective Y5 receptor antagonist blocked the Y5 agonist-induced analgesic-like effect. The present study indicates involvement of Y5 receptors probably at the supraspinal level in mediation of NPY agonist-induced analgesic-like effects in the hot plate test.