Modulation of [3H]3-((±)-2-carboxypiperazin-4-yl)propyl-1-phosphonic acid ([3H]CPP) binding by ligands acting at the glycine and the polyamine sites of the rat brain NMDA receptor complex

摘要: Abstract The competitive N-methyl-D-aspartate (NMDA) receptor antagonist [ 3 H ]3-((±)-2- caboxypiperazin -4- yl ) propyl -1- phosphonic acid ([3H]CPP) interacts with two discrete binding sites, one of high- and the other low-affinity, on rat forebrain synaptic plasma membranes. high affinity site exhibited a Kd 101.5 nM Bmax 2.01 pmol/mg, while for low was 4.11 μM 19.7 pmol/mg. glycine antagonists 3-amino-1-hydroxy-2-pyrrolidone (HA-966), l-aminocyclobutanecarboxyli: (ACBC), agonist l-aminocyclopropanccarboxylic (ACC) itself (as well as polyamines spermine spermidine), enhanced [3H]CPP binding. When subjected to saturation analysis, this enhancement found primarily involve an increase in component Neither parameters were affected. Although similar observed polyamines, effects these classes ligands additive, consistent their having actions at different recognition sites NMDA complex.