Spinal Noradrenergic Modulation and the Role of the Alpha-2 Receptor in the Antinociceptive Effect of Intrathecal Nefopam in the Formalin Test
The Korean Journal of Pain
; : 23-29, 2014.
Article
em En
| WPRIM
| ID: wpr-48136
Biblioteca responsável:
WPRO
ABSTRACT
BACKGROUND:
Nefopam has shown an analgesic effect on acute pain including postoperative pain. The reuptake of monoamines including serotonin and noradrenaline has been proposed as the mechanism of the analgesic action of nefopam, but it remains unclear. Although alpha-adrenergic agents are being widely used in the perioperative period, the role of noradrenergic modulation in the analgesic effect of nefopam has not been fully addressed.METHODS:
Changes in the antinociceptive effect of intrathecal (i.t.) nefopam against formalin-elicited flinching responses were explored in Sprague-Dawley rats pretreated with i.t. 6-hydroxydopamine (6-OHDA), which depletes spinal noradrenaline. In addition, antagonism to the effect of nefopam by prazosin and yohimbine was evaluated to further elucidate the antinociceptive mechanism of i.t. nefopam.RESULTS:
Pretreatment with i.t. 6-OHDA alone did not alter the flinching responses in either phase of the formalin test, while it attenuated the antinociceptive effect of i.t. nefopam significantly during phase 1, but not phase 2. The antagonist of the alpha-2 receptor, but not the alpha-1 receptor, reduced partially, but significantly, the antinociceptive effect of i.t. nefopam during phase 1, but not during phase 2.CONCLUSIONS:
This study demonstrates that spinal noradrenergic modulation plays an important role in the antinociceptive effect of i.t. nefopam against formalin-elicited acute initial pain, but not facilitated pain, and this action involves the spinal alpha-2 but not the alpha-1 receptor.Palavras-chave
Texto completo:
1
Índice:
WPRIM
Assunto principal:
Dor Pós-Operatória
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Medula Espinal
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Ioimbina
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Medição da Dor
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Prazosina
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Serotonina
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Norepinefrina
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Oxidopamina
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Ratos Sprague-Dawley
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Período Perioperatório
Idioma:
En
Revista:
The Korean Journal of Pain
Ano de publicação:
2014
Tipo de documento:
Article