Characterisation of the binding of [3H]MDL 105,519, a radiolabelled antagonist for the N-methyl-D-aspartate-associated glycine site, to pig cortical brain membranes.
Binding of [3H]MDL 105,519 to glycine sites on N-methyl-D-aspartate (NMDA) receptors of pig cortical brain membranes was evaluated. [3H]MDL 105,519 labelled a homogeneous population of binding sites with a Kd-value of 3.73 +/- 0.43 nM and a Bmax-value of 3030 +/- 330 fmol/mg protein. Clear correlations between the affinity (Ki) to [3H]MDL 105,519 labelled sites and the potency (EC50) to enhance or inhibit non-equilibrium [3H]MK-801 binding in the nominal absence of glycine were shown for a variety of glycine site agonists, partial agonists and antagonists. The ratio of Ki to EC50 was >1 for agonists and partial agonists and <1 for antagonists. Various cations as well as glutamate and polyamine site ligands were shown to be able to influence [3H]MDL 105,519 binding to pig cortical brain membranes substantially.
Höfner
G
G
Institut für Pharmazie und Lebensmittelchemie, München, Germany.
Wanner
K T
KT
D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000378:metabolism; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D018691:Excitatory Amino Acid Antagonists / Q000378:metabolism* / Q000494:pharmacology; D005998:Glycine; D007211:Indoles / Q000378:metabolism*; D007700:Kinetics; D011869:Radioligand Assay; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D013552:Swine; D014316:Tritium
D018690:Excitatory Amino Acid Agonists; D018691:Excitatory Amino Acid Antagonists; D007211:Indoles; C101788:MDL 105519; D016194:Receptors, N-Methyl-D-Aspartate; D014316:Tritium; D016291:Dizocilpine Maleate; D005998:Glycine