Mh. Makman et al., PRESENCE AND CHARACTERIZATION OF NOCICEPTIN (ORPHANIN FQ) RECEPTOR-BINDING IN ADULT-RAT AND HUMAN FETAL HYPOTHALAMUS, Brain research, 762(1-2), 1997, pp. 247-250
High affinity and saturable nociceptin (orphanin FQ) receptors were de
tected and characterized in adult rat and human fetal hypothalamic mem
branes, utilizing [I-125]Tyr(12)-nociceptin as ligand. Nociceptin boun
d with picomolar affinity, dynorphin A with nanomolar affinity, naloxo
ne and dynorphan A(1-8) with micromolar while des-Tyr(1)-dynorphin (dy
norphin A(2-17)), several other opioids, morphine and benzomorphans fa
iled to compete for binding at 1-10 mu M. Gpp(NH)p together with sodiu
m ion markedly decreased binding, consistent with involvement of a G p
rotein-linked receptor. (C) 1997 Elsevier Science B.V.