Selective opioid receptor agonist and antagonist displacement of [3H]naloxone binding in amphibian brain

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Opioid receptor ligands have been shown to elicit antinociception in mammals through three distinct types of receptors designated as μ, δ and κ. These opioid receptors have been characterized and cloned in several mammalian species. Radioligand binding techniques were employed to characterize the sites of opioid action in the amphibian, Rana pipiens. Naloxone is a general opioid receptor antagonist which has not been characterized in R. pipiens. Kinetic analyses of [3H]naloxone in the amphibian yielded a K(D) of 6.84 nM while the experimentally derived K(D) value from saturation experiments was found to be 7.11 nM. Density data were also determined from saturation analyses which yielded a B(max) of 2170 fmol/mg. Additionally, K(i) values were calculated in competition studies for various unlabelled μ-, δ- and κ-opioid receptor ligands to isolate their site of action. Highly selective antagonists for μ-, δ- and κ-opioid receptors yielded nearly identical K(i) values against [3H]naloxone. (C) 2000 Elsevier Science B.V.

Original languageEnglish
Pages (from-to)255-262
Number of pages8
JournalEuropean Journal of Pharmacology
Volume397
Issue number2-3
DOIs
StatePublished - 2 Jun 2000

Keywords

  • Amphibian
  • Antinociception
  • Opioid receptor
  • [H]Naloxone

Fingerprint Dive into the research topics of 'Selective opioid receptor agonist and antagonist displacement of [<sup>3</sup>H]naloxone binding in amphibian brain'. Together they form a unique fingerprint.

Cite this