Effects of NaOCl on Neuronal Excitability and Intracellular Calcium Concentration in Rat Spinal Substantia Gelatinosa Neurons
International Journal of Oral Biology
; : 5-12, 2013.
Article
em Ko
| WPRIM
| ID: wpr-102158
Biblioteca responsável:
WPRO
ABSTRACT
Recent studies indicate that reactive oxygen species (ROS) can act as modulators of neuronal activity, and are critically involved in persistent pain primarily through spinal mechanisms. In this study, we investigated the effects of NaOCl, a ROS donor, on neuronal excitability and the intracellular calcium concentration ([Ca2+]i) in spinal substantia gelatinosa (SG) neurons. In current clamp conditions, the application of NaOCl caused a membrane depolarization, which was inhibited by pretreatment with phenyl-N-tert-buthylnitrone (PBN), a ROS scavenger. The NaOCl-induced depolarization was not blocked however by pretreatment with dithiothreitol, a sulfhydryl-reducing agent. Confocal scanning laser microscopy was used to confirm whether NaOCl increases the intracellular ROS level. ROS-induced fluorescence intensity was found to be increased during perfusion of NaOCl after the loading of 2',7'-dichlorofluorescin diacetate (H2DCF-DA). NaOCl-induced depolarization was not blocked by pretreatment with external Ca2+ free solution or by the addition of nifedifine. However, when slices were pretreated with the Ca2+ ATPase inhibitor thapsigargin, NaOCl failed to induce membrane depolarization. In a calcium imaging technique using the Ca2+-sensitive fluorescence dye fura-2, the [Ca2+]i was found to be increased by NaOCl. These results indicate that NaOCl activates the excitability of SG neurons via the modulation of the intracellular calcium concentration, and suggest that ROS induces nociception through a central sensitization.
Palavras-chave
Texto completo:
1
Base de dados:
WPRIM
Assunto principal:
Perfusão
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Substância Gelatinosa
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Doadores de Tecidos
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Cálcio
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Fura-2
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Espécies Reativas de Oxigênio
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ATPases Transportadoras de Cálcio
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Microscopia Confocal
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Tapsigargina
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Ditiotreitol
Limite:
Animals
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Humans
Idioma:
Ko
Revista:
International Journal of Oral Biology
Ano de publicação:
2013
Tipo de documento:
Article