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Papers of the Week

Papers: 9 Feb 2019 - 15 Feb 2019

Animal Studies, Pharmacology/Drug Development

2019 Jun

Neurol Res



COX-2 contributed to the remifentanil-induced hyperalgesia related to ephrinB/EphB signaling.


Peng Y, Zang T, Zhou L, Ni K, Zhou X
Neurol Res. 2019 Jun; 41(6):519-527.
PMID: 30759061.


Background and Objectives: Studying the underlying mechanisms of opiate-induced hyperalgesia is fundamental to understanding and treating pain. Our previous study has proved that ephrinB/EphB signaling contributes to opiate-induced hyperagesia, but the manner in which ephrinB/EphB signaling acts on spinal nociceptive information networks to produce hyperalgesia remains unclear. Other studies have suggested that ephrinB/EphB signaling, NMDA receptor and COX-2 act together to participate in the modulation of nociceptive information processes at the spinal level. The objective of this research was to investigate the role of COX-2 in remifentanil-induced hyperalgesia and its relationship with ephrinB/EphB signaling. Methods: We characterized the remifentanil-induced pain behaviours by evaluating thermal hyperalgesia and mechanical allodynia in a mouse hind paw incisional model. Protein expression of COX-2 in spinal cord was assayed by western blotting and mRNA level of COX-2 was assayed by Real-time PCR (RT-PCR). Results: Continuing infusion of remifentanil produced thermal hyperalgesia and mechanical allodynia, which was accompanied by increased expression of spinal COX-2 protein and mRNA. This response was inhibited by pre-treatment with EphB2-Fc, an antagonist of ephrinB/EphB. SC58125 and NS398, inhibitors of COX-2, suppressed pain behaviours induced by remifentanil infusion and reversed the increased pain behaviours induced by intrathecal injection of ephrinB2-Fc, an agonist of ephrinB/EphB. Conclusions: Our findings confirmed that COX-2 is involved in remifentanil-induced hyperalgesia related to ephrinB/EphB signaling. EphrinB/EphB signaling might be the upstream of COX-2.