HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Selective and interactive down-regulation of mu- and delta-opioid receptors in human neuroblastoma SK-N-SH cells.

Abstract
Human neuroblastoma SK-N-SH cells, which contain both mu- and delta-opioid receptors, were grown under conditions that provided a mu:delta ratio of 1.5:1. Both receptors were down-regulated after 72 hr of exposure to 100 nM etorphine. Selective down-regulation was demonstrated using selective opioid agonists; the mu agonist Tyr-D-Ala2-Gly-(Me)Phe4-Gly-ol down-regulated mu- but not delta-opioid receptors, whereas prolonged exposure to the selective delta agonist D-Pen2,D-Pen5-enkephalin resulted in delta- but not mu-opioid receptor down-regulation. Morphine, which binds mu- as well as delta-opioid receptors, down-regulated both receptor subtypes. NG108-15 cells, which contain delta receptors exclusively, were also tested. NG108-15 cells did not exhibit delta-opioid receptor down-regulation when exposed to morphine. The discrepancy between the effect of chronic morphine treatment on delta receptors in SK-N-SH cells and in NG108-15 cells raised the question of whether the coexistence of mu receptors in the former allowed morphine to down-regulate delta receptors. The role of mu-opioid receptors in morphine-induced delta receptor down-regulation was studied by using the irreversible mu antagonist beta-funaltrexamine. Pretreatment of SK-N-SH cells with beta-funaltrexamine prevented down-regulation of delta receptors in response to chronic exposure to morphine but did not affect down-regulation of delta receptors in response to D-Pen2,D-Pen5-enkephalin. The experimental data indicate that morphine-induced delta-opioid receptor down-regulation is dependent on the presence of functional mu receptors in the same cell.
AuthorsY Baumhaker, M Gafni, O Keren, Y Sarne
JournalMolecular pharmacology (Mol Pharmacol) Vol. 44 Issue 2 Pg. 461-7 (Aug 1993) ISSN: 0026-895X [Print] United States
PMID8394999 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
Chemical References
  • Analgesics
  • Enkephalins
  • Pyrrolidines
  • Receptors, Opioid, delta
  • Receptors, Opioid, mu
  • Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
  • Naltrexone
  • 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
  • beta-funaltrexamine
  • Morphine
  • Enkephalin, D-Penicillamine (2,5)-
Topics
  • 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer
  • Analgesics (pharmacology)
  • Down-Regulation (drug effects)
  • Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
  • Enkephalin, D-Penicillamine (2,5)-
  • Enkephalins (pharmacology)
  • Humans
  • Morphine (pharmacology)
  • Naltrexone (analogs & derivatives, pharmacology)
  • Neuroblastoma (pathology)
  • Pyrrolidines (pharmacology)
  • Receptors, Opioid, delta (drug effects, metabolism)
  • Receptors, Opioid, mu (drug effects, metabolism)
  • Tumor Cells, Cultured

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: