Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Más filtros

Banco de datos
Tipo de estudio
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
J Membr Biol ; 251(1): 163-178, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29379989

RESUMEN

Major voltage-activated ionic channels of stellate cells in the ventral part of cochlear nucleus (CN) were largely characterized previously. However, it is not known if these cells are equipped with other ion channels apart from the voltage-sensitive ones. In the current study, it was aimed to study subunit composition and function of ATP-sensitive potassium channels (KATP) in stellate cells of the ventral cochlear nucleus. Subunits of KATP channels, Kir6.1, Kir6.2, SUR1, and SUR2, were expressed at the mRNA level and at the protein level in the mouse VCN tissue. The specific and clearly visible bands for all subunits but that for Kir6.1 were seen in Western blot. Using immunohistochemical staining technique, stellate cells were strongly labeled with SUR1 and Kir6.2 antibodies and moderately labeled with SUR2 antibody, whereas the labeling signals for Kir6.1 were too weak. In patch clamp recordings, KATP agonists including cromakalim (50 µM), diazoxide (0.2 mM), 3-Amino-1,2,4-triazole (ATZ) (1 mM), 2,2-Dithiobis (5-nitro pyridine) (DTNP) (330 µM), 6-Chloro-3-isopropylamino- 4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide (NNC 55-0118) (1 µM), 6-chloro-3-(methylcyclopropyl)amino-4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide (NN414) (1 µM), and H2O2 (0.88 mM) induced marked responses in stellate cells, characterized by membrane hyperpolarization which were blocked by KATP antagonists. Blockers of KATP channels, glibenclamide (0.2 mM), tolbutamide (0.1 mM) as well as 5-hydroxydecanoic acid (1 mM), and catalase (500 IU/ml) caused depolarization of stellate cells, increasing spontaneous action potential firing. In conclusion, KATP channels seemed to be composed dominantly of Kir 6.2 subunit and SUR1 and SUR2 and activation or inhibition of KATP channels regulates firing properties of stellate cells by means of influencing resting membrane potential and input resistance.


Asunto(s)
Núcleo Coclear/efectos de los fármacos , Núcleo Coclear/metabolismo , Canales de Potasio de Rectificación Interna/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Óxidos S-Cíclicos/farmacología , Diazóxido/análogos & derivados , Diazóxido/farmacología , Peróxido de Hidrógeno , Canales KATP/agonistas , Canales KATP/antagonistas & inhibidores , Canales KATP/metabolismo , Ratones , Ratones Endogámicos BALB C , Canales de Potasio de Rectificación Interna/agonistas , Canales de Potasio de Rectificación Interna/antagonistas & inhibidores , Tolbutamida/farmacología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA