ZIB

Treffer pro Seite

Treffer 1 - 2 | 2 Treffer

Sortierung

Digitale Medien

Regulation of ion channels in rat hepatocytes (1997)

Breit, S. ; Kolb, H.-A. ; Apfel, H. ; [weitere]

Springer

Pflügers Archiv 435 (1997), S. 203-210

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-2013

Schlagwort(e): Key words Patch clamp ; Cell membrane potential ; K+ conductance ; K+ channels ; Cl ; channels ; cAMP ; Cell volume ; Progesterone ; Hepatocytes

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Abstract 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.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/s004240050502

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Exposure of perfused liver to hypotonic conditions modifies cellular nitrogen metabolism (1990)

Häussinger, D. ; Lang, F.

New York, N.Y. : Wiley-Blackwell

Journal of Cellular Biochemistry 43 (1990), S. 355-361

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0730-2312

Schlagwort(e): cell volume ; glutamine ; ammonia ; urea synthesis ; metabolic regulation ; Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Chemie und Pharmazie , Medizin

Notizen: Isolated livers were exposed to hypotonic perfusates. As shown previously, this hypotonic challenge leads to initial cell swelling, followed by volume regulatory ion fluxes, largely restoring cell volume within approximately 6 min. However, the hepatocyte is left in an altered metabolic state, which is characterized by marked stimulation of hepatic glutamine uptake and degradation and transient release of glutamate from the liver. Urea formation from glutamine and alanine is stimulated, whereas hepatic ammonia uptake and utilization for urea and glutamine synthesis decreases. These observations reveal a hitherto unrecognized factor modulating hepatic function during intestinal absorption.

Zusätzliches Material: 3 Ill.