Regulation of ion channels in rat hepatocytes.
Pflugers Arch
; 435(2): 203-10, 1998 Jan.
Article
en En
| MEDLINE
| ID: mdl-9382932
Patch-clamp studies have been performed to elucidate single ion channels in rat hepatocytes. In rat hepatocytes two types of ion channel have been identified: an inwardly rectifying K+ channel with a mean inward conductance of 55 +/- 6.5 pS (n = 20) and a mean outward conductance of 25 +/- 3.2 pS (n = 20) in the inside-out configuration with 145 mmol/l KCl on either side of the patch as well as an outwardly rectifying Cl- channel with a mean outward conductance of 30 +/- 4.5 pS (n = 8) and a mean inward conductance of 10 +/- 2.3 pS (n = 6) in the inside-out configuration with symmetrical 145 mmol/l KCl. The open probability of these channels is virtually insensitive to Ca2+ activity on the intracellular side. Accordingly, the Ca2+ ionophore ionomycin had no effect on cell membrane potential. Dibutyryl-cAMP (db-cAMP) hyperpolarizes the cell membrane and increases the activity of the 55-pS inwardly rectifying K+ channel by reducing the duration of closure between bursts. Forskolin similarly hyperpolarizes the cell membrane. The inwardly rectifying K+ channel is inhibited by progesterone, while the outwardly rectifying Cl- channel is insensitive to progesterone.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Canales Iónicos
/
Hígado
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Pflugers Arch
Año:
1998
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Alemania