NMDA RECEPTOR ANTAGONIST APV INHIBITED THE NOCICEPTIVE BEHAVIORAL RESPONSES PROVOKED BY SUBCUTANEOUS INJECTION OF FORMALIN INTO THE PLANTAR OF THE RAT LEFT HINDFOOT

AIM: To check the analgesic effect of DL-2-amino-5-phosphonovaleric acid (APV), an NMDA receptor antagonist, on the nociceptive behavioral responses provoked by formalin. METHODS: Inject subcutaneously 50 μl of 2.5% formalin into the plantar of the rat hindfoot. Administer APV intrathecally and then analyze possible inhibitory effect of APV on nociceptive behavioral responses. RESULTS: APV dose-dependently inhibited these persevering nociceptive behavioral response, the effect was characterized by a time-reaction; but the inhibition of flinching response led by APV showed no characteristic for time-reaction. CONCLUSION: NMDA receptor importantly participates in the neural transmission and modulation of nociception in the spinal cord. Whether or not NMDA receptor antagonist (APV) play direct role in ameliorating nociceptive behavioral responses should be further ascertained.