Cl- and K+ conductances activated by cell swelling in primary cultures of rabbit distal bright convoluted tubules.
Am J Physiol
; 273(5): F680-97, 1997 11.
Article
em En
| MEDLINE
| ID: mdl-9374831
ABSTRACT
Ionic currents induced by cell swelling were characterized in primary cultures of rabbit distal bright convoluted tubule (DCTb) by the whole cell patch-clamp technique. Cl- currents were produced spontaneously by whole cell recording with an isotonic pipette solution or by exposure to a hypotonic stress. Initial Cl- currents exhibited outwardly rectifying current-voltage relationship, whereas steady-state currents showed strong decay with depolarizing pulses. The ion selectivity sequence was I- = Br- > Cl- >> glutamate. Currents were inhibited by 0.1 mM 5-nitro-2-(3-phenylpropylamino) benzoic acid and 1 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid and strongly blocked by 1 mM diphenylamine-2-carboxylate. Currents were insensitive to intracellular Ca2+ but required the presence of extracellular Ca2+. They were not activated in cells pretreated with 200 nM staurosporine, 50 microM LaCl3, 10 microM nifedipine, 100 microM verapamil, 5 microM tamoxifen, and 50 microM dideoxyforskolin. Staurosporine, tamoxifen, verapamil, or the absence of external Ca2+ was without effect on the fully developed Cl- currents. Osmotic shock also activated K+ currents in Cl- free conditions. These currents were time independent, activated at depolarized potentials, and inhibited by 5 mM BaCl2. The activation of Cl- and K+ currents by an osmotic shock may be implicated in regulatory volume decrease in DCTb cells.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
/
Canais de Cloreto
/
Túbulos Renais Distais
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
França