Orexin A human, rat, mouse is a 33 amino acid excitatory neuropeptide. Orexin A human, rat, mouse works on 2 specific G protein-coupled receptors (GPCRs): orexin-1 (OX1) and orexin-2 (OX2).
SB408124 Hcl is a non-peptide antagonist for OX1 receptor with Ki of 57 nM and 27 nM in both whole cell and membrane, respectively; exhibits 50-fold selectivity over OX2 receptor.