Peri-sciatic administration of indomethacin early after nerve injury can attenuate the development of tactile allodynia in a rat model of L5 single spinal nerve injury.

Abstract

To clarify the role of cyclooxygenase in the peripheral nerve on the development of neuropathic pain, we investigated the effects of peri-sciatic administration of indomethacin on the development of allodynia in a model of L5 single spinal nerve injury. Peri-sciatic administration of indomethacin (1 mg/kg) was performed 3, 24, or 72 h after nerve injury (n=6/each). In rats with indomethacin 3 or 24 h after nerve injury, ipsi-lateral paw withdrawal thresholds 7-35 days after nerve injury were significantly higher compared with those in the control group (n=6: without peri-sciatic treatment) (P<0.05). However, such efficacy was no longer apparent when indomethacin was administered 72 h after nerve injury. These results suggest that peri-sciatic administration of indomethacin early (less than 24 h) after nerve injury can attenuate the development of allodynia.