Agmatine inhibits NMDA receptor-mediated calcium transients in mouse spinal cord dorsal horn via intact PSD95-nNOS signaling.

Intrathecal administration of agmatine, an NMDA receptor (NMDAr) antagonist and nitric oxide synthase inhibitor, prevents neuropathic pain behavior in a dose-dependent manner by acting at the GluN2B subunit of the NMDAr. The present study investigated the pharmacological mechanism of agmatine's inhibitory effect using calcium imaging and an in vivo assay of nociceptive responses induced by NMDA. The application of NMDA-evoked calcium transients in the mouse spinal cord dorsal horn slice was inhibited by the NMDAr antagonist, 2-amino-5-phosphonovalerate.