[Analgesic effect of COX inhibitors and its mechanism in a rat model of neuropathic pain].
OBJECTIVE
To investigate the effect of COX inhibitors on pain threshold and spinal N-methyl-D-aspartate (NMDA) receptor subunit 2B (NR2B) expression in a rat model of neuropathic pain.


METHODS
Thirty-six male SD rats were randomly divided into sham-operated group, chronic constriction injury (CCI) of the sciatic nerve group, indomethacin+CCI group, and parecoxib+CCI group with corresponding treatments. All the rats were tested for mechanical withdrawal threshold, and at day 13 after the surgery, the rats were decapitated for detection of NR2B expression in the spinal cord at the L4-6 levels.


RESULTS
The mechanical withdrawal threshold were lowered significantly after the operation in CCI, indomethacin+CCI and parecoxib+CCI groups (P<0.05). Parecoxib alleviated the hypersensitivity of CCI model rats but not affected spinal NR2B expressions (P>0.05). No significant differences were found in the mechanical withdrawal threshold or spinal NR2B expression between CCI group and indomethacin+CCI group (P>0.05).


CONCLUSIONS
Parecoxib can alleviate neuropathic hypersensitivity in rats, but this effect may not be associated with NR2B expression in the spinal cord.
Department of Anesthesiology, Guangdong General Hospital, Guangzhou, China. yw72@163.com
Guo-bin
GB
Zhou
Hong-ying
HY
Li
Jin-quan
JQ
Ji
Wei
W
Yu
Wei-tao
WT
Ma
D000700:Analgesics / Q000627:therapeutic use*; D000818:Animals; D003250:Constriction; D052246:Cyclooxygenase 2 Inhibitors / Q000627:therapeutic use*; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D009437:Neuralgia / Q000188:drug therapy* / Q000209:etiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D012584:Sciatic Nerve / Q000293:injuries; D013116:Spinal Cord / Q000378:metabolism
D000700:Analgesics; D052246:Cyclooxygenase 2 Inhibitors; D007555:Isoxazoles; C121001:NR2B NMDA receptor; D016194:Receptors, N-Methyl-D-Aspartate; C409945:parecoxib