Chloride conductance determining membrane potential of rabbit articular chondrocytes.
J Membr Biol
; 185(1): 75-81, 2002 Jan 01.
Article
en En
| MEDLINE
| ID: mdl-11891566
ABSTRACT
Membrane conductance of cultured rabbit articular chondrocytes was characterized by means of the patch-clamp technique. The resting membrane potential of the articular chondrocytes was about -42 mV. The membrane potential shifted in accordance with the prediction by the Nernst equation for Cl- when intracellular and extracellular concentrations of Cl- were changed. On the other hand, change in extracellular concentration of K+ produced no shift in the membrane potential of chondrocytes. The Cl- channel blocker 4-acetamido-4'-isothiocyanatostilbene-2'2-disulfonic acid (SITS) depolarized the membrane potential. These findings suggest that the membrane potential of the chondrocytes is determined mainly by Cl- conductance. Using the cell-attached patch-clamp method, a large unitary conductance of 217 pS was observed in the articular chondrocytes. The unitary current was reversibly blocked by SITS. Therefore, the unitary current was carried by Cl-. The Cl- channel showed voltage-dependent activation and the channels exhibited long-lasting openings. Therefore, the membrane potential of rabbit cultured articular chondrocytes was mainly determined by the activities of the large-conductance and voltage-dependent Cl- channels.
Buscar en Google
Base de datos:
MEDLINE
Asunto principal:
Activación del Canal Iónico
/
Canales de Cloruro
/
Condrocitos
/
Potenciales de la Membrana
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
J Membr Biol
Año:
2002
Tipo del documento:
Article