title: Differential regulation of multiple neuroreceptors in a somatic cell hybrid by inhibitors of glycoprotein processing.
abstract: Specific binding of [3H][D-Ala2,D-Leu5]enkephalin, [3H]ethylketocyclazocine, 5-[3H]hydroxytryptamine, and [3H]spiperone was examined in neuroblastoma-brain hybrid cell line NCB-20 following exposure to inhibitors of N-linked protein glycosylation (tunicamycin, TM) and oligosaccharide processing (swainsonine, SW). TM treatment reduced ligand binding at delta- and sigma-opiate receptors and neuroleptic binding sites (20 to 50% of control), with no discernible effect on the binding properties of 5HT1-serotonin receptors. In contrast, exposure to SW resulted in a three-fold increase in binding capacity of sigma-receptors, while decreasing receptor affinity for ligand. SW treatment did not alter ligand interactions with either sigma-receptors or neuroleptic binding sites, but did reduce specific binding of serotonin to 5HT1-receptors. The effects of TM and SW on distinct receptor subpopulations were further demonstrated by attenuation of opiate and serotonin-mediated regulation of intracellular cyclic AMP.
mesh_terms: D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D001921:Brain; D006224:Cricetinae; D003412:Cricetulus; D000242:Cyclic AMP / Q000378:metabolism; D005944:Glucosamine / Q000031:analogs & derivatives*; D006023:Glycoproteins / Q000096:biosynthesis*; D006822:Hybrid Cells; D006863:Hydrogen-Ion Concentration; D051379:Mice; D009447:Neuroblastoma; D011499:Protein Processing, Post-Translational / Q000187:drug effects*; D011954:Receptors, Dopamine / Q000187:drug effects; D017981:Receptors, Neurotransmitter / Q000187:drug effects*; D011957:Receptors, Opioid / Q000187:drug effects; D017465:Receptors, Opioid, delta; D011985:Receptors, Serotonin / Q000187:drug effects; D017480:Receptors, sigma; D017026:Swainsonine; D014415:Tunicamycin / Q000494:pharmacology*
chemical_list: D000470:Alkaloids; D006023:Glycoproteins; D011954:Receptors, Dopamine; D017981:Receptors, Neurotransmitter; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D011985:Receptors, Serotonin; D017480:Receptors, sigma; C031611:spiroperidol receptor; D014415:Tunicamycin; D000242:Cyclic AMP; D005944:Glucosamine; D017026:Swainsonine