Rapid agonist-induced loss of 125I-beta-endorphin opioid receptor sites in NG108-15, but not SK-N-SH neuroblastoma cells

• Published in: Life sciences (1973) Vol. 49; no. 19; p. PL147
• Main Authors: Cone, R I, Lameh, J, Sadée, W
• Format: Journal Article
• Language: English
• Published: Netherlands 1991
• Subjects: Analgesics - pharmacology; Animals; beta-Endorphin - metabolism; Binding Sites - drug effects; Enkephalin, Ala-MePhe-Gly; Enkephalin, D-Penicillamine (2,5); Enkephalin, Leucine-2-Alanine - pharmacology; Enkephalins - pharmacology; Humans; Mice; Neuroblastoma - metabolism; Receptors, Opioid - drug effects; Receptors, Opioid - metabolism; Receptors, Opioid, delta; Receptors, Opioid, mu; Tumor Cells, Cultured - metabolism
• ISSN: 0024-3205
• DOI: 10.1016/0024-3205(91)90396-S

We have measured mu and delta opioid receptor sites on intact SK-N-SH and NG108-15 neuroblastoma cells, respectively, in culture. Use of 125I-beta-endorphin (beta E) as a tracer, together with beta E(6-31) to block high-affinity non-opioid binding in both cell lines, permitted the measurement of cell surface mu and delta opioid receptor sites. Labeling was at delta sites in NG108-15 cells and predominantly at mu sites in SK-N-SH cells. Pretreatment with the mu and delta agonist, DADLE, caused a rapid loss of cell surface delta receptor sites in NG108-15 cells, but failed to reduce significantly mu receptor density in SK-N-SH cells.