The Effects of Pre-emptive Administration of Ketamine and norBNI on Pain Behavior, c-Fos, and Prodynorphin Protein Expression in the Rat Spinal Cord after Formalin-induced Pain Is Modulated by the DREAM Protein.
10.3344/kjp.2013.26.3.255
- Author:
Idris LONG
1
;
Rapeah SUPPIAN
;
Zalina ISMAIL
Author Information
1. BRAINetwork Centre for Neurocognitive Science, School of Health Sciences, Health Campus, Universiti Sains Malaysia, Kelantan, Malaysia. idris@kk.usm.my
- Publication Type:Original Article
- Keywords:
DREAM protein;
formalin test;
kappa opioid receptor;
NMDA receptor;
rat spinal cord
- MeSH:
Animals;
Blotting, Western;
Enkephalins;
Formaldehyde;
Humans;
Immunohistochemistry;
Ketamine;
Male;
N-Methylaspartate;
Neurons;
Pain Measurement;
Protein Precursors;
Proteins;
Rats;
Rats, Sprague-Dawley;
Receptors, Opioid, kappa;
Spinal Cord
- From:The Korean Journal of Pain
2013;26(3):255-264
- CountryRepublic of Korea
- Language:English
-
Abstract:
BACKGROUND: We investigated the effects of pre-emptive administration of ketamine and norBNI on pain behavior and the expression of DREAM, c-Fos, and prodynorphin proteins on the ipsilateral side of the rat spinal cord at 2 and 4 hours after formalin injection. METHODS: Eighty-four male Sprague Dawley rats were divided into 4 major groups consisting of control rats (C) (n = 12), rats given only formalin injections (F) (n = 24), and rats treated with pre-emptive administration of either ketamine (K+F) (n = 24) or norBNI (N+F) (n = 24). The non-control groups were further divided into subgroups consisting of rats that were sacrificed at 2 and 4 hours (n = 12 for each group) after formalin injection. Pain behavior was recorded for 1 hour. After 2 and 4 hours, the rats were sacrificed and the spinal cords (L4-L5 sections) were removed for immunohistochemistry and Western blot analysis. RESULTS: The pain behavior response was reduced in the K+F group compared to the other groups during the second phase of the formalin pain response. We detected an increase in the nuclear DREAM protein level in the K+F group at 2 and 4 hours and a transient decrease in the N+F group at 2 hours; however, it increased at 4 hours after injection. Fos-like immunoreactivity (FLI) and Prodynorphin-like immunoreactivity (PLI) neurons decreased in the K+F group but increased in the N+F group at 2 hours after injection. While FLI decreased, PLI increased in all groups at 4 hours after injection. CONCLUSIONS: We suggest that NMDA and kappa opioid receptors can modulate DREAM protein expression, which can affect pain behavior and protein transcriptional processes at 2 hours and bring about either harmful or protective effects at 4 hours after formalin injection.
