Pharmacological analysis of dopamine stimulation of [35S]-GTP gamma S binding via human D2short and D2long dopamine receptors expressed in recombinant cells

Br J Pharmacol. 1996 Jul;118(6):1544-50. doi: 10.1111/j.1476-5381.1996.tb15572.x.


1. The activation of G-proteins by agonist-occupied D2 or D3 dopamine receptors in membranes from recombinant cells expressing the cloned receptors has been analysed by a [35S]-guanosine 5'-[gamma-thio] triphosphate ([35S]-GTP gamma S) binding assay. 2. The rate of [35S]-GTP gamma S binding was increased by dopamine in a dose-dependent manner in membranes from CHO cells stably expressing either the D2short or D2long dopamine receptor. 3. The dopamine-induced stimulation of [35S]-GTP gamma S binding could be inhibited by a range of antagonists. Affinities for antagonists derived from the inhibition of the dopamine stimulation of [35S]-GTP gamma S binding correlated very well with affinities derived from radioligand binding studies. 4. When the maximum [35S]-GTP gamma S binding responses stimulated by dopamine acting at different receptor subtypes were compared, there was a tendency for the stimulation via the D2short receptor to be greater than via the D2long receptor and for the stimulation via the D3 dopamine receptor to be less than for either D2 receptor. These differences in maximal response were also seen when the inhibitory effects of dopamine on adenylyl cyclase via the three receptor subtypes were compared. 5. The stimulation of [35S]-GTP gamma S binding by dopamine in membranes from recombinant cells therefore provides an excellent system for studying the molecular nature of agonism and the receptor/G-protein interactions for these receptors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Animals
  • CHO Cells
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Cells, Cultured
  • Colforsin / antagonists & inhibitors
  • Colforsin / pharmacology
  • Cricetinae
  • Cyclic AMP / metabolism
  • Dopamine / pharmacology*
  • Dopamine Antagonists / pharmacology
  • GTP-Binding Proteins / metabolism
  • Guanosine 5'-O-(3-Thiotriphosphate) / metabolism*
  • Guanosine Diphosphate / pharmacology
  • Humans
  • Kinetics
  • Radioligand Assay
  • Receptors, Dopamine D2 / drug effects
  • Receptors, Dopamine D2 / genetics
  • Receptors, Dopamine D2 / metabolism*
  • Receptors, Dopamine D3
  • Recombination, Genetic
  • Stimulation, Chemical


  • DRD3 protein, human
  • Dopamine Antagonists
  • Receptors, Dopamine D2
  • Receptors, Dopamine D3
  • Guanosine Diphosphate
  • Colforsin
  • Guanosine 5'-O-(3-Thiotriphosphate)
  • Cyclic AMP
  • GTP-Binding Proteins
  • Adenylyl Cyclases
  • Dopamine