Pharmacological properties of recombinant human N-methyl-D-aspartate receptors comprising NR1a/NR2A and NR1a/NR2B subunit assemblies expressed in permanently transfected mouse fibroblast cells.

摘要: The pharmacological properties of two recombinant human N-methyl-D-aspartate (NMDA) receptor subtypes, comprising either NR1a/NR2A or NR1a/NR2B subunits permanently transfected into mouse L(tk-) cells, have been compared using whole-cell voltage-clamp electrophysiology. Glutamate was a full agonist at both receptors, having modestly but statistically significant (p < 0.002) higher affinity for the NR2B- than NR2A-containing (microscopic Kd [mKd] = 0.76 and 0.43 microM, respectively). In comparison to glutamate, NMDA, quinolinic acid, cis-2,3-piperidinedicarboxylic acid were partial agonists subtypes. Maximal amplitude currents resulted when glutamate-site combined with glycine D-serine; these amino acids were, therefore, defined as site. Glycine had an approximately 10-fold 0.0001) receptors (mKd 0.057 0.53 D-Cycloserine, (+)-(3R)-3-amino-1-hydroxypyrrolidin-2-one, (+)-cis-(4R)-methyl-(3R)-amino-1-hydroxypyrrolidin-2-one, 1-aminocyclobutanecarboxylic also affinities NR2B-containing agonists, unlike glycine. Agonist-evoked antagonized by D-(-)-2-amino-5-phosphonopentanoic cis-4-(phosphonomethyl)piperidine-2-carboxylic 3-((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic all which slightly, significant, (2.2-, 2.8-, 5.5-fold, respectively) receptor. Responses glycine-site antagonists 7-chlorokynurenic 7-chloro-4-hydroxy-3-(3-phenoxy)phenylquinolin-2-(1H)-one, (+/=)-4-(trans)-2-carboxy-5,7-dichloro-4-phenylaminocarbonylamino- 1,2,3,4- tetrahydroquinoline. atypical NMDA antagonist ifenprodil showed largest separation in functional (IC50 values, 0.6 175 microM These experiments demonstrate usefulness cells electrophysiological studies function provide first detailed analysis