Increased cerebral nuclear factor kappa B in a complex regional pain syndrome rat model: possible relationship between peripheral injury and the brain

Francis Sahngun Nahm; Sang-Soep Nahm; Woong Ki Han; Ho Young Gil; Eunjoo Choi; Pyung Bok Lee

doi:10.2147/JPR.S166270

Increased cerebral nuclear factor kappa B in a complex regional pain syndrome rat model: possible relationship between peripheral injury and the brain

J Pain Res. 2019 Mar 6:12:909-914. doi: 10.2147/JPR.S166270. eCollection 2019.

Authors

Francis Sahngun Nahm^{1

2}, Sang-Soep Nahm³, Woong Ki Han¹, Ho Young Gil⁴, Eunjoo Choi¹, Pyung Bok Lee^{1

2}

Affiliations

¹ Department of Anesthesiology and Pain Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea, painfree@snubh.org.
² College of Medicine, Seoul National University, Seoul, South Korea, painfree@snubh.org.
³ Laboratory of Veterinary Anatomy, College of Veterinary Medicine, Konkuk University, Seoul, South Korea.
⁴ Department of Anesthesiology and Pain Medicine, Ajou University Hospital, Suwon, South Korea.

Abstract

Purpose: Complex regional pain syndrome (CRPS) is a rare but refractory pain disorder. Recent advanced information retrieval studies using text-mining and network analysis have suggested nuclear factor kappa B (NFκB) as a possible central mediator of CRPS. The brain is also known to play important roles in CRPS. The aim of this study was to evaluate changes in cerebral NFκB in rats with CRPS.

Materials and methods: The chronic post-ischemia perfusion (CPIP) model was used as the CRPS animal model. O-rings were applied to the left hind paws of the rats. The rats were categorized into three groups according to the results of behavioral tests: the CPIP-positive (A) group, the CPIP-negative (B) group, and the control (C) group. Three weeks after the CPIP procedure, the right cerebrums of the animals were harvested to measure NFκB levels using an ELISA.

Results: Animals in group A had significantly decreased mechanical pain thresholds (P<0.01) and significantly increased cerebral NFκB when compared to those in groups B and C (P=0.024).

Conclusion: This finding indicates that peripheral injury increases cerebral NFκB levels and implies that minor peripheral injury can lead to the activation of pain-related cerebral processes in CRPS.

Keywords: cerebrum; complex regional pain syndrome; enzyme-linked immune-sorbent assay; nuclear factor kappa B; pain.