Contralateral allodynia and central change in the chronic post-ischemic pain model rats.
10.4097/kjae.2009.56.4.419
- Author:
Kyung Hwa KWAK
1
;
Kyung Young JUNG
;
Jy Young CHOI
;
Taeha RYU
;
Jin Seok YEO
;
Sung Sik PARK
;
Dong Gun LIM
;
Si Oh KIM
;
Woon Yi BAEK
;
Jung Gil HONG
Author Information
1. Department of Anesthesiology and Pain Medicine, Kyungpook National University School of Medicine, Daegu, Korea. dglim@mail.knu.ac.kr
- Publication Type:Original Article
- Keywords:
Chronic post-ischemia pain;
Complex regional pain syndrome-type I;
NMDA receptor;
Mirror-image allodynia
- MeSH:
Animals;
Blotting, Western;
Central Nervous System Sensitization;
Complex Regional Pain Syndromes;
Humans;
Hyperalgesia;
Inositol Phosphates;
Male;
N-Methylaspartate;
Phosphorylation;
Prostaglandins E;
Rats;
Rats, Sprague-Dawley;
Reperfusion;
Specific Gravity;
Spinal Cord;
Tourniquets
- From:Korean Journal of Anesthesiology
2009;56(4):419-424
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Mirror-image allodynia is a mysterious phenomenon that occurs in association with many clinical pain syndromes including complex regional pain syndromes (CRPS). Underlying mechanisms for the development of such pain are still a matter of investigation. Several studies suggest that activation of the N-methyl-D-aspartate (NMDA) receptor is essential for central sensitization as a base for persistent pain. The aim is to assess whether alteration of NMDA receptor expression correlates with the contralateral allodynia in the chronic post-ischemia pain (CPIP) model rats representing CRPS-Type I. METHODS: Application of a tight-fitting tourniquet for a period of 3 hours before reperfusion produced CPIP in male Sprague-Dawley rats. The mechanical paw withdrawal thresholds to von Frey stimuli (using a dynamic plantar aesthesiometer) were measured as pain indicators in ipsilateral and contralateral hindpaws. Phosphorylation of the NMDA receptor 1 subunit (pNR1), assessed with Western blot, was measured in the contralateral L4-6 spinal cord. RESULTS: Ipsilateral and contralateral mechanical allodynia is present at 4 hours after reperfusion, peaked at 3 days, and continued for 7 days after reperfusion. The relative density of pNR1 of CPIP rats significantly decreased in the contralateral L4-6 spinal cord compared to baseline value (P < 0.05). There was significant correlation between paw withdrawal threshold and the relative density of pNR1 (ipsilateral; R2 = 0.75, P < 0.01, contralateral; R2 = 0.60, P < 0.01). CONCLUSIONS: These data suggest that pNR1 is correlated to the contralateral mechanical allodynia in CPIP rats.
