Role of N-methyl-D-aspartate receptor in acute spinal cord injury.

To clarify the role of N-methyl-D-aspartate (NMDA) receptors in acute spinal cord injury, changes in the intraspinal microcirculation after acute spinal cord injury in rabbits were examined. Systemic administration of MK-801, an NMDA receptor antagonist, at a dose of 5 mg/kg, significantly improved motor recovery after injury and significantly reduced edema formation at the injured site without altering spinal cord blood flow or vascular permeability at the injured site. These findings indicate that excitatory amino acids contribute to secondary spinal cord damage, especially edema formation, mediated by NMDA receptors in the early stage after injury.