Korean J Crit Care Med.  2005 Jun;20(1):24-31.

The Effects of Intrathecal Ketamine and NBQX on Neurologic Injury and Spinal Cord Glutamate Receptor mRNA Expression in Transient Spinal Ischemia in the Rat

• Baek SH
• Hong JM
• Chung KS

Abstract

BACKGROUND
Spinal cord injury occurring as the result of surgical repair of thoracic and thoracoabdominal aortic disease remains a devastating complication. Excitatory amino acids have been known to cause neurologic injury after neuronal ischemia. The purpose of this study was to elucidate the effects of intrathecal ketamine or NBQX on neurologic outcome and NMDA receptor gene expression in transient spinal ischemia. METHODS: Sprague-Dawley rats were anesthetized with enflurane, divided by 4 groups: Control (C group), Intrathecal ketamine 0.1 mg (K-1 group), Intrathecal ketamine 0.2 mg (K-2 group), and intrathecal NBQX 1 nM (N group). Spinal ischemia was produced by both induced hypotension and thoracic aortic cross clamping. After spinal ischemia, neurologic scores were assessed after 1, 2, 3 hours. After 3 hours rats were euthenized and spinal cords were removed for the assay of NMDAR and mGlu1 mRNA. RESULTS: The neurol ogic scores of K-2 and N groups were significantly lower than C group and K-1 group. There were no significant difference between K-1 group and C group. The NMDAR and mGlu1 gene expression was increase in C and K-1 group compared to sham operation. In K-2 and N groups, the gene expressions were significantly lesser than C group. CONCLUSIONS: The NMDAR and mGlu1 gene expressions were increased in transient spinal ischemia. Intrathecal ketamine and NBQX were effective in preventing neurologic injury after transient spinal ischemia. The NMDA antagonistic action of ketamine might involve to prevent neurologic injury.

Keyword

Ketamine; NBQX; NMDA receptor; Spinal ischemia

MeSH Terms

Animals
Aortic Diseases
Constriction
Enflurane
Excitatory Amino Acids
Gene Expression
Glutamic Acid*
Hypotension
Ischemia*
Ketamine*
N-Methylaspartate
Neurons
Rats*
Rats, Sprague-Dawley
Receptors, Glutamate*
RNA, Messenger*
Spinal Cord Injuries
Spinal Cord*
Enflurane
Excitatory Amino Acids
Glutamic Acid
Ketamine
N-Methylaspartate
RNA, Messenger
Receptors, Glutamate