| Registro completo |
| Provedor de dados: |
BJMBR
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| País: |
Brazil
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| Título: |
Participation of ATP-sensitive K+ channels in the peripheral antinociceptive effect of fentanyl in rats
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| Autores: |
Rodrigues,A.R.A.
Castro,M.S.A.
Francischi,J.N.
Perez,A.C.
Duarte,I.D.G.
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| Data: |
2005-01-01
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| Ano: |
2005
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| Palavras-chave: |
Peripheral antinociception
Fentanyl
K+ channel
Μ-Opioid receptor agonist
Glibenclamide
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| Resumo: |
We examined the effect of several K+ channel blockers such as glibenclamide, tolbutamide, charybdotoxin (ChTX), apamin, tetraethylammonium chloride (TEA), 4-aminopyridine (4-AP), and cesium on the ability of fentanyl, a clinically used selective µ-opioid receptor agonist, to promote peripheral antinociception. Antinociception was measured by the paw pressure test in male Wistar rats weighing 180-250 g (N = 5 animals per group). Carrageenan (250 µg/paw) decreased the threshold of responsiveness to noxious pressure (delta = 188.1 ± 5.3 g). This mechanical hyperalgesia was reduced by fentanyl (0.5, 1.5 and 3 µg/paw) in a peripherally mediated and dose-dependent fashion (17.3, 45.3 and 62.6%, respectively). The selective blockers of ATP-sensitive K+ channels glibenclamide (40, 80 and 160 µg/paw) and tolbutamide (80, 160 and 240 µg/paw) dose dependently antagonized the antinociception induced by fentanyl (1.5 µg/paw). In contrast, the effect of fentanyl was unaffected by the large conductance Ca2+-activated K+ channel blocker ChTX (2 µg/paw), the small conductance Ca2+-activated K+ channel blocker apamin (10 µg/paw), or the non-specific K+ channel blocker TEA (150 µg/paw), 4-AP (50 µg/paw), and cesium (250 µg/paw). These results extend previously reported data on the peripheral analgesic effect of morphine and fentanyl, suggesting for the first time that the peripheral µ-opioid receptor-mediated antinociceptive effect of fentanyl depends on activation of ATP-sensitive, but not other, K+ channels.
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| Tipo: |
Info:eu-repo/semantics/article
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| Idioma: |
Inglês
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| Identificador: |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000100014
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| Editor: |
Associação Brasileira de Divulgação Científica
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| Relação: |
10.1590/S0100-879X2005000100014
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| Formato: |
text/html
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| Fonte: |
Brazilian Journal of Medical and Biological Research v.38 n.1 2005
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| Direitos: |
info:eu-repo/semantics/openAccess
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