Differences in G-protein activation by μ- and δ-opioid, and cannabinoid, receptors in rat striatum

https://doi.org/10.1016/0014-2999(96)00211-7Get rights and content

Abstract

Receptor activation of G-proteins can be measured by agonist-stimulated [35S]GTPγS binding in the presence of excess guanosine diphosphate (GDP). To determine whether opioid and cannabinoid receptor-mediated G-protein activation correlate with their receptor densities, this study compared opioid- and cannabinoid-stimulated [35S]guanylyl-5′-O-(γ-thio)-triphosphate (GTPγS) binding with the corresponding Bmax values of receptor binding in rat striatum. Scatchard analysis revealed that the Bmax of cannabinoid receptor binding was approximately ten times higher than that of μ- or δ-opioid receptor binding. However, comparable levels of cannabinoid- and μ- and δ-opioid-stimulated [35S]GTPγS binding were observed in the caudate-putamen by [35S]GTPγS autoradiography in brain sections. Scatchard analysis of net agonist-stimulated [35S]GTPγS binding in membranes showed that the Bmax of cannabinoid-stimulated binding was only twice that of μ- or δ-opioid-stimulated binding. Thus, the calculated amplification factors for μ- and δ-opioid receptors are seven times that of cannabinoid receptors.

References (48)

  • H. Kurose et al.

    Specific uncoupling by islet-activating, pertussis toxin, of negative signal transduction via α-adrenergic, cholinergic, and opiate receptors in neuroblastoma x glioma hybrid cells

    J. Biol. Chem.

    (1983)
  • P. Mailleux et al.

    Immunohistochemical distribution of neurons containing the G-proteins GG11α in the adult rat brain

    Neuroscience

    (1992)
  • A. McKnight et al.

    The opioid receptors in the hamster vas deferens are of the δ type

    Neuropharmacology

    (1985)
  • S. Offermanns et al.

    What are the functions of the pertussis toxin-insensitive G proteins G12, G13 and Gz?

    Mol. Cell. Endocrinol.

    (1994)
  • S.E. Senogles et al.

    Specificity of receptor-G protein interactions

    J. Biol. Chem.

    (1990)
  • N. Aronin et al.

    The subcellular localization of the G-protein G in the basal ganglia revcals its potential role in both signal transduction and vesicle trafficking

    J. Neurosci.

    (1992)
  • T. Asano et al.

    Immunochemical and immunohistochemical localization of the G protein G in rat central nervous tissues

    J. Biochem.

    (1990)
  • L. Birnbaumer et al.

    Studies on the intrinsic activity (efficacy) of human adrenergic receptors

    Tex. Heart Inst. J.

    (1994)
  • Y. Chen et al.

    Molecular cloning and functional expression of a μ-opioid receptor from rat brain

    Mol. Pharmacol.

    (1993)
  • S.R. Childers et al.

    Differential regulation by guanine nucleotides of opiate agonist and antagonist receptor interactions

    J. Neurochem.

    (1980)
  • T. Costa et al.

    Spontaneous association between opioid receptors and GTP-binding proteins in native membranes: specific regulation by antagonists and sodium ions

    Mol. Pharmacol.

    (1990)
  • W.A. Devane et al.

    Determination and characterization of a cannabinoid receptor in rat brain

    Mol. Pharmacol.

    (1988)
  • C.J. Evans et al.

    Cloning of a delta opioid receptor by functional expression

    Science

    (1992)
  • P. Gierschik et al.

    Signal amplification in HL-60 granulocytes: Evidence that the chemotactic peptide receptor catalytically activates guanine-nucleotide-binding regulatory proteins in native plasma membranes

    Eur. J. Biochem.

    (1991)
  • Cited by (0)

    View full text