Analysis of NMDA receptors in the human spinal cord.
NMDA receptors in postmortem human spinal cord were analyzed using [3H]MK-801 ligand binding and immunoblotting with NMDA receptor subunit-specific antibodies. The average KD for [3H]MK-801 binding was 1.77 nM with a Bmax of 0.103 pmol/mg. The EC50 for stimulation of -3H-MK-801 binding with L-glutamate was 0.34 microM. None of these parameters were affected by postmortem intervals up to 72 h. Immunoblotting of native NMDA receptors showed that NR1, NR2A, NR2C, and NR2D subunits could all be found in the human spinal cord of which NR1 was preferentially located to the dorsal half. Immunoprecipitation of solubilized receptors revealed that NR1, NR2C, and NR2D subunits coprecipitated with the NR2A subunit, indicating that native human spinal cord NMDA receptors are heteroligimeric receptors assembled by at least three different receptor subunits. These results provide a basis for the development of drugs selectively aimed at spinal cord NMDA receptors for the future treatment of spinal cord disorders.
T10 T11 T12 T13 T14 T15 T16 T17 T18 T19 T1 T20 T21 T22 T23 T24 T25 T26 T27 T2 T3 T4 T5 T6 T7 T8 T9
CHEMICAL CHEMICAL GENE-N GENE-N GENE-N GENE-Y GENE-Y GENE-N GENE-Y GENE-Y CHEMICAL GENE-Y GENE-N GENE-Y GENE-Y GENE-N GENE-N GENE-N GENE-N CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL CHEMICAL
NMDA NMDA NMDA receptors NMDA receptor NMDA receptors NR1 NR2A NR2C NR2D NR1 NMDA NR1 NR2C NR2D NR2A NMDA receptors heteroligimeric receptors NMDA receptors NMDA receptors NMDA [3H]MK-801 3H-MK-801 L-glutamate NMDA [3H]MK-801 NMDA heteroligimeric