N-methyl-D-aspartate antagonist inhibits NR-1 subunit phosphorylation of the spinal N-methyl-D-aspartate receptor induced by low frequency electroacupuncture.

We investigated whether the 2 Hz electroacupuncture (EA) analgesia is associated with phosphorylation of N-methyl-D-aspartate receptor (NMDAR) NR-1 subunits and NMDAR antagonism in the lumbar spinal cord of rats. EA stimulation produced an increase of serine phosphorylation of NMDAR NR-1 subunits in the spinal cord as compared with normal conditions. However, the intrathecal injection of NMDAR antagonist D-2-amino-5-phosphonopentanoic acid significantly prevented serine phosphorylation of NMDAR NR-1 subunits induced by EA stimulation in the dorsal horn of spinal cord.