Potent agonist of the nociceptin (ORL1) receptor, demonstrated both in vitro and in vivo. Selective, competitive antagonism at the nociceptin receptor has also been reported (pA2 = 7.02 and 6.75 in the guinea pig ileum and mouse vas deferens respectively)
Ac-hMCH(6-16)-NH2 shows non-selective agonist activity towards both MCH-1R and MCH-2R, which are human MCH receptors in the brain. The compound effectively binds to and activates these receptors, with IC 50 values of 0.16 nM and 2.7 nM for MCH-1R and MCH-2R, respectively.
Ac-RYYRWK-NH2 is a highly effective and specific partial agonist for the nociceptin receptor (NOP). It demonstrates a remarkable affinity for rat cortical membranes ORL1, with [3H]Ac-RYYRWK-NH2 exhibiting a Kd value of 0.071 nM. However, it shows negligible affinity towards μ-, κ-, or δ-opioid receptors.
Potent, selective partial agonist peptide for the NOP receptor (Ki = 0.71 nM). Selective over μ, δ and κ opioid receptors (IC50 > 4000 nM). Increases food intake in vivo.
High affinity ligand for the NOP site (Ki = 1.5 nM). Antagonizes nociceptin-stimulated GTP binding in rat brain and the chronotropic effect of nociceptin on rat cardiomyocytes. However, displays potent agonist properties in vivo, inhibiting locomotor acti