Biochemical and pharmacological characterization of cannabinoid binding sites using [3H]SR141716A

Neuroreport. 1996 Feb 29;7(3):789-92. doi: 10.1097/00001756-199602290-00026.

Abstract

This study describes the binding characteristics of cannabinoid binding sites expressed in rat cerebellar membranes using the tritiated derivative of SR141716A, the newly described cannabinoid receptor antagonist. A single population of high-affinity binding sites (K(D) = 0.59 +/- 0.08 nM; Bmax = 3.86 +/- 0.42 pmol mg-1 of protein) was demonstrated. Kinetic, competition and saturation experiments give similar results in terms of SR141716A affinity. delta 9-tetrahydrocannabinol and the 11-hydroxy derivative competitively inhibited the specific binding of [3H]SR141716A (Ki = 47 +/- 9 and 32 +/- 4 nM, respectively). The cannabinoid agonist WIN55212-2 has a 25-fold lower affinity for [3H]SR141716A than for [3H]WIN55212-2, showing that the two ligands do not recognize the cannabinoid binding site in the same fashion.

MeSH terms

  • Analgesics / metabolism
  • Analgesics / pharmacokinetics
  • Animals
  • Benzoxazines
  • Binding, Competitive / drug effects
  • Cannabinoids / pharmacology
  • Cerebellum / drug effects
  • Cerebellum / metabolism*
  • In Vitro Techniques
  • Male
  • Membranes / drug effects
  • Membranes / metabolism
  • Morpholines / metabolism
  • Morpholines / pharmacokinetics
  • Naphthalenes / metabolism
  • Naphthalenes / pharmacokinetics
  • Piperidines* / antagonists & inhibitors
  • Piperidines* / pharmacokinetics
  • Pyrazoles* / antagonists & inhibitors
  • Pyrazoles* / pharmacokinetics
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Cannabinoid
  • Receptors, Drug / drug effects*
  • Receptors, Drug / metabolism*
  • Rimonabant

Substances

  • Analgesics
  • Benzoxazines
  • Cannabinoids
  • Morpholines
  • Naphthalenes
  • Piperidines
  • Pyrazoles
  • Receptors, Cannabinoid
  • Receptors, Drug
  • (3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone
  • Rimonabant