Inhibitory effects of retigabine, a Kv7 channel activator, on mechanosensitive primary bladder afferent activities and nociceptive behaviors in rats.
Neurourol Urodyn
; 36(2): 280-285, 2017 02.
Article
em En
| MEDLINE
| ID: mdl-26536146
ABSTRACT
AIMS:
Kv7 voltage-gated potassium channels have been suggested to modulate mechano-afferent transduction and nociception in the bladder. We investigated the effects of retigabine, a Kv7 channel activator, on rhythmic bladder contractions (RBCs), and single-unit afferent activities (SAAs) of the primary bladder mechanosensitive afferent nerve fibers in urethane-anesthetized rats. In addition, the effects of pretreatment with retigabine on the nociceptive behaviors provoked by an intravesical instillation of resiniferatoxin (RTX) were evaluated in the conscious condition.METHODS:
Female Sprague-Dawley rats were used. Under urethane anesthesia, saline was instilled into the bladder until RBCs were induced reproducibly. Then, the effects of intravenous, cumulative administrations of retigabine (0.1-3 mg/kg) or vehicle (saline) on RBCs were assessed. In separate animals, SAAs of Aδ- and C-fibers were identified by electrical stimulation of the pelvic nerve and by bladder distention with saline. After baseline recording, vehicle or retigabine (0.01-1 mg/kg) was administered intravenously and further recordings were performed. Under pretreatment with vehicle or retigabine (3 mg/kg intraperitoneally), the frequencies of lower abdominal licking and freezing were counted and scored as the bladder nociceptive behaviors induced by intravesical RTX instillation (3 µM, 0.3 ml).RESULTS:
Retigabine dose-dependently decreased both the frequency and the amplitude of RBCs and SAAs of both Aδ- and C-fibers. The effect on RBCs was more potent on the frequency than the amplitude. Retigabine inhibited the RTX-induced abdominal licking, but not freezing.CONCLUSION:
Kv7 channels are likely to be implicated in inhibition of bladder mechano- and nociceptive sensory transduction. Neurourol. Urodynam. 36280-285, 2017. © 2015 Wiley Periodicals, Inc.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fenilenodiaminas
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Comportamento Animal
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Bexiga Urinária
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Carbamatos
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Canais de Potássio de Abertura Dependente da Tensão da Membrana
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Mecanotransdução Celular
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Moduladores de Transporte de Membrana
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Nociceptividade
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Neurônios Aferentes
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Neurourol Urodyn
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Japão