Mechanical Antiallodynic Effect of Intrathecal Nefopam in a Rat Neuropathic Pain Model.
10.3346/jkms.2015.30.8.1189
- Author:
Kyung Hoon KIM
1
,
2
;
Gyeong Jo BYEON
;
Hee Young KIM
;
Seung Hoon BAEK
;
Sang Wook SHIN
;
Sung Tae KOO
Author Information
1. Department of Anesthesia and Pain Medicine, Pusan National University School of Medicine
2. Research Institute for Convergence of biomedical science and technology Pusan National University Yangsan Hospital, Yangsan, Korea. byeongj@pusan.ac.kr
- Publication Type:Original Article ; Research Support, Non-U.S. Gov't
- Keywords:
Mechanical Allodynia;
Nefopam;
Neuropathic Pain;
Spinal Nerve Ligation
- MeSH:
Analgesics, Non-Narcotic/administration & dosage;
Animals;
Dose-Response Relationship, Drug;
Hyperalgesia/*drug therapy/etiology/*physiopathology;
Injections, Spinal;
Male;
Nefopam/*administration & dosage;
Neuralgia/complications/*drug therapy/*physiopathology;
Pain Measurement/drug effects;
Pain Perception/*drug effects;
Rats;
Rats, Sprague-Dawley;
Treatment Outcome
- From:Journal of Korean Medical Science
2015;30(8):1189-1196
- CountryRepublic of Korea
- Language:English
-
Abstract:
Nefopam has a pharmacologic profile distinct from that of opioids or other anti-inflammatory drugs. Several recent studies demonstrate that nefopam has a mechanism of action similar to those of anti-depressants and anticonvulsants for treating neuropathic pain. The present study investigates the mechanical antiallodynic effect of nefopam using immunohistochemical study and western blot analysis in a rat neuropathic pain model. Twenty-eight male Sprague-Dawley rats were subjected to left fifth lumbar (L5) spinal nerve ligation and intrathecal catheter implantation, procedures which were not performed on the 7 male Sprague-Dawley rats in the sham surgery group (group S). Nefopam, either 10 or 100 microg/kg (group N10 or N100, respectively), and normal saline (group C) were intrathecally administered into the catheter every day for 14 days. The mechanical allodynic threshold of intrathecal nefopam was measured using a dynamic plantar aesthesiometer. Immunohistochemistry targeting cluster of differentiation molecule 11b (CD11b) and glial fibrillary acidic protein (GFAP) was performed on the harvested spinal cord at the level of L5. Extracellular signal-regulated kinase 1/2 (ERK 1/2) and cyclic adenosine monophosphate response element binding protein (CREB) were measured using western blot analysis. The N10 and N100 groups showed improved mechanical allodynic threshold, reduced CD11b and GFAP expression, and attenuated ERK 1/2 and CREB in the affected L5 spinal cord. In conclusion, intrathecal nefopam reduced mechanical allodynia in a rat neuropathic pain model. Its mechanical antiallodynic effect is associated with inhibition of glial activation and suppression of the transcription factors' mitogen-activated protein kinases in the spinal cord.
