The delta-opioid receptor in neuroblastoma x glioma NG 108-15 hybrid cells is strongly precoupled to a G-protein.
Neuroblastoma x glioma NG 108-15 hybrid cells contain a homogeneous population of delta-opioid receptors. NG 108-15 membranes were labelled either with the opiate agonist, [3H]etorphine or the opiate antagonist [3H]diprenorphine under various conditions: absence or presence of Na+ and/or 5'-guanylylimidophosphate (GppNHp). Ultracentrifugation in linear sucrose gradients after digitonin solubilization of prelabeled receptor was performed. In the soluble extracts from NG 108-15 hybrid cell membranes, bound [3H]etorphine and bound [3H]diprenorphine sedimented in the same position, even in the presence of NaCl and/or GppNHp. These data were analyzed in terms of relative agonist potency of diprenorphine on this specific model, using equilibrium binding studies and inhibition of adenylate cyclase activity. Diprenorphine, at the concentrations used for sedimentation studies, behaving as an opiate antagonist, it is concluded that the delta-opioid receptor could be strongly precoupled to the G-protein in the NG 108-15 cell.
Polastron
J
J
Unité de Neuropharmacologie Moléculaire, C.N.R.S. UPR 8221, Toulouse, France.
Jauzac
P
P
Meunier
J C
JC
D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005910:Glioma / Q000378:metabolism; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D006822:Hybrid Cells; D051379:Mice; D009294:Narcotics / Q000494:pharmacology; D009423:Nervous System Neoplasms / Q000378:metabolism; D009447:Neuroblastoma / Q000378:metabolism; D051381:Rats; D011957:Receptors, Opioid / Q000378:metabolism*; D017465:Receptors, Opioid, delta; D014407:Tumor Cells, Cultured
D000067956:Adenylyl Cyclase Inhibitors; D009294:Narcotics; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D006165:Guanylyl Imidodiphosphate; D019204:GTP-Binding Proteins; D000262:Adenylyl Cyclases