Orphanin FQ/nociceptin and naloxone benzoylhydrazone activate distinct receptors in BE(2)-C human neuroblastoma cells.
kappa(3) opioid receptors have a unique binding and analgesic profile, as originally defined by naloxone benzoylhydrazone (NalBzoH). Although antisense studies demonstrated the close relationship between kappa(3) opioid and Orphan opioid receptor-like receptor (ORL1) and implied they were generated from the same gene, these studies also revealed differences in the sensitivity profiles of NalBzoH and orphanin FQ/nociceptin (OFQ/N), indicating that they were not identical. To help define the relationship between kappa(3) and ORL1 receptors, we utilized BE(2)-C human neuroblastoma cells that natively express functional ORL1 and kappa(3) opioid receptors. (125)I-[Tyr(14)]OFQ/N binds to a single population of receptors in BE(2)-C cells. Competition binding and adenylyl cyclase studies clearly illustrated marked selectivity differences between the ORL1 and the kappa(3) sites. Furthermore, antisense DNA targeting ORL1 blocked the inhibition of cAMP by OFQ/N, but not by NalBzoH. Thus, the receptor mechanisms mediating the activity of OFQ/N and NalBzoH in BE(2)-C cells are distinct.
Mathis
J P
JP
The Cotzias Laboratory of Neuro-Oncology, Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Mandyam
C D
CD
Altememi
G F
GF
Pasternak
G W
GW
Standifer
K M
KM
D016375:Antisense Elements (Genetics) / Q000494:pharmacology; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D001667:Binding, Competitive / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology*; D009447:Neuroblastoma; D018847:Opioid Peptides / Q000378:metabolism / Q000494:pharmacology*; D011869:Radioligand Assay; D011957:Receptors, Opioid / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D017473:Receptors, Opioid, kappa / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000187:drug effects* / Q000378:metabolism; D000094942:Nociceptin Receptor; D000097629:Nociceptin
D016375:Antisense Elements (Genetics); D000242:Cyclic AMP; D009270:Naloxone; D018847:Opioid Peptides; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C058380:naloxone benzoylhydrazone; C000722283:OPRL1 protein, human