SK-N-BE: a human neuroblastoma cell line containing two subtypes of delta-opioid receptors.
A human neuroblastoma cell line, SK-N-BE, was shown to express a substantial amount of opioid receptors (200-300 fmol/mg of protein). A ligand binding profile of these receptors revealed that they could belong to two distinct subtypes of delta-opioid receptors. Results from sucrose-gradient sedimentation experiments were compared with similar data obtained with the mu-opioid receptor of the rabbit cerebellum and the delta-opioid receptor of the hybrid NG108-15 cell line and have shown that the opioid receptor of the SK-N-BE cell line behaved hydrodynamically as an intermediate between mu- and delta-opioid receptors. Taken together, pharmacological and hydrodynamic studies suggest that the opioid receptors present in the SK-N-BE cell membranes could belong to two delta-opioid receptor subtypes interacting allosterically. Functional experiments suggest that at least one of these subtypes of delta-opioid receptor is negatively coupled to the adenylate cyclase via a Gi protein and that the opiate receptors of the SK-N-BE neuroblastoma cell line undergo a rapid down-regulation when preincubated in the presence of the high-affinity opioid, etorphine.
Polastron
J
J
Laboratoire de Pharmacologie et de Toxicologie Fondamentales, CNRS UPR 8221, Toulouse, France.
Mur
M
M
Mazarguil
H
H
Puget
A
A
Meunier
J C
JC
Jauzac
P
P
D000262:Adenylyl Cyclases / Q000378:metabolism; D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D004174:Diprenorphine / Q000378:metabolism; D015536:Down-Regulation; D005048:Etorphine / Q000378:metabolism / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D008024:Ligands; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D017465:Receptors, Opioid, delta / Q000145:classification / Q000187:drug effects / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D008024:Ligands; D017465:Receptors, Opioid, delta; D004174:Diprenorphine; D005048:Etorphine; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases