Fast and slow voltage modulation of apical Cl- permeability in toad skin at high [K+]
Braz. j. med. biol. res
;
30(8): 1033-44, Aug. 1997. ilus
Artículo
en Inglés
| LILACS
| ID: lil-197262
ABSTRACT
The influence of voltage on the conductance of toad skin was studied to identify the time course of the activation/deactivation dynamics of voltage-dependent Cl- channels located in the apical membrane of mitochondrion-rich cells in this tissue. Positive apical voltage induced an important conductance inhibition which took a few seconds to fully develop and was instantaneously released by pulse inversion to negative voltage, indicating a short-duration memory of the inhibiting factors. Sinusoidal stimulation at 23.4 mM [Cl-] showed hysteresis in the current versus voltage curves, even at very low frequency, suggesting that the rate of voltage application was also relevant for the inhibition/releasing effect to develop. We conclude that the voltage modulation of apical Cl- permeability is essentially a fast process and the apparent slow components of activation/deactivation obtained in the whole skin are a consequence of a gradual voltage build-up across the apical membrane due to voltage sharing between apical and basolateral membranes.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Potasio
/
Técnicas In Vitro
/
Permeabilidad de la Membrana Celular
/
Canales de Cloruro
Tipo de estudio:
Estudio pronóstico
Límite:
Animales
Idioma:
Inglés
Revista:
Braz. j. med. biol. res
Asunto de la revista:
Biologia
/
Medicina
Año:
1997
Tipo del documento:
Artículo
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