Regulation of ion channels in rat hepatocytes
| Autor: | Jürg Graf, Dieter Häussinger, H.-A. Kolb, Florian Lang, Samuel N. Breit, C. Haberland, Horst Apfel, M. Schmitt |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Patch-Clamp Techniques
Potassium Channels Physiology Clinical Biochemistry Ionophore Ion Channels Membrane Potentials Potassium Chloride chemistry.chemical_compound Chloride Channels Physiology (medical) Animals Humans Ion channel Membrane potential Ionomycin Colforsin Electric Conductivity Cardiac action potential Hyperpolarization (biology) Calcium-activated potassium channel Rats chemistry Bucladesine Liver Biophysics Ligand-gated ion channel Calcium Ion Channel Gating |
| Zdroj: | Pflugers Archiv : European journal of physiology. 435(2) |
| ISSN: | 0031-6768 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink