title: Up-regulation of opiate receptors by opiate antagonists in neuroblastoma-glioma cell culture: the possibility of interaction with guanosine triphosphate-binding proteins.
abstract: Neuroblastoma-glioma NG108-15 cells that were cultured for 48 h with the opiate antagonist, naloxone, respond to the guanosine 5'-triphosphate (GTP) analogue guanosine 5'-[beta, gamma-imido]-triphosphate (GMP-PNP) in the binding assay as the control, non-treated, cells. This was observed when the guanyl nucleotide was tested in the presence or absence of sodium chloride and also after subcellular fractionation of the membranes on a sucrose gradient which separated between two receptor-containing fractions. The findings suggest that the increase in delta type enkephalin receptors in naloxone-treated NG108-15 cells does not reflect an alteration in the interaction between the receptor and the adenylate cyclase-GTP-binding protein system.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000378:metabolism; D016308:Enkephalin, Leucine-2-Alanine; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005910:Glioma; D006160:Guanosine Triphosphate / Q000494:pharmacology; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology*; D009447:Neuroblastoma; D051381:Rats; D011957:Receptors, Opioid / Q000187:drug effects* / Q000378:metabolism; D017465:Receptors, Opioid, delta
chemical_list: D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D006165:Guanylyl Imidodiphosphate; D009270:Naloxone; D004743:Enkephalin, Leucine; D016308:Enkephalin, Leucine-2-Alanine; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins