Modulation by extracellular and intracellular iodide of volume-activated Cl- current in HeLa cells

Stutzin, A; Eguiguren, AL; Montes, N; Sepulveda, FV

Abstract

The patch-clamp technique was used to study the effect of extracellular and intracellular iodide on the properties of the volume-activated anion current in HeLa cells. Upon hypotonic challenge, HeLa cells responded by activating an outwardly rectifying Cl- current. Replacement of extracellular Cl- by I-, a more permeable anion, increased the peak outward and inward current, reduced the magnitude of deactivation observed at depolarized potentials and shifted the half-maximal (V-0.5) deactivation voltage towards more positive values. On the other hand, when internal Cl- was replaced by I- the volume-activated current was not observed in normal, Cl--rich hypotonic extracellular solution. However, switching to a hypotonic extracellular solution containing a mixture of Cl- and I- resulted in the activation of the volume-sensitive current. Furthermore, once the current was activated, I- could be excluded from the external solution without significantly affecting the current properties These results suggest that the permeant anion plays a crucial role in the gating mechanism of the volume-activated Cl- current, influencing the swelling-dependent activation and the voltage-dependent deactivation processes.

Más información

Título según WOS: ID WOS:000073618700020 Not found in local WOS DB
Título de la Revista: PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
Volumen: 436
Número: 1
Editorial: Springer
Fecha de publicación: 1998
Página de inicio: 152
Página final: 154
DOI:

10.1007/s004240050616

Notas: ISI