OrphaninFQ(nociceptin,OFQ),aheptadecapeptidepeptide,hasbeendesignatedasanendogenousligandfortheORL1receptor.TheaminoacidsequenceofOFQhashomologywithotheropioidpeptides,especiallytheprodynorphinfragmentdynorphinA,suggestingacloseevolutionaryrelationshipbetweentheprecursors.AdiffusedistributionthroughoutthebrainisseenwithbindingstudiesandinsituhybridizationsuggestinganextensiveroleforOFQinamultitudeofCNSfunctions.ImmunocytochemicallocalizationsinratspinalcordhavedemonstratedOFQabundanceinsuperficialdorsalhorn,lateralspinalnucleusandtheregiondorsaltothecentralcanal.OFQimmunoreactivitywasnotaffectedbydorsalrhizotomy,indicatingthatinspinalcordthepeptideisproducedbycentralratherthanprimaryafferentneurons.Thelocalizationissupportedbyitsfunctioninprocessingofnociceptivesignals.
Specifications: