Ion channels involved in insulin release are activated by osmotic swelling of pancreatic B-cells
| Autor: | Günther Zempel, Florian Lang, S. Britsch, Peter Krippeit-Drews, Gisela Drews, Nubia Kristen Kaba, Gillian L. Busch |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Intracellular Fluid
medicine.medical_specialty Potassium Channels Anion channel Biophysics Mice Inbred Strains Biochemistry Ion Channels Membrane Potentials Islets of Langerhans Mice Adenosine Triphosphate Pancreatic B-cell Chloride Channels Osmotic Pressure Internal medicine Extracellular medicine Osmotic pressure Animals Insulin Membrane potential KATP channel Voltage-dependent calcium channel Chemistry Depolarization Biological Transport Cell Biology Hyperpolarization (biology) Endocrinology Osmotic cell swelling Chloride channel Female Calcium Channels Intracellular |
| Zdroj: | Biochimica et biophysica acta. 1370(1) |
| ISSN: | 0006-3002 |
| Popis: | Measurements of the membrane potential showed that osmotic swelling (−80mosmol/l) of pancreatic B-cells led to a transient hyperpolarization followed by a more sustained depolarization of the cell membrane. Cell swelling triggers a transient activation of the K+ATP current and of an inward current, carried by Cl−. This current was inhibited by DIDS, D600, and by omission of extracellular Ca2+. The depolarization opens voltage dependent L-type Ca2+ channels, thereby increasing the intracellular Ca2+ activity ([Ca2+]i). This effect was blunted by D600 or abolished by omission of Ca2+. Moreover, osmotic swelling transiently increased the amplitude of the Ca2+ currents. Replacement of NaCl by d-mannitol proved that the observed effects are due to an increase in cell volume and not to a reduction of extracellular Na+ or Cl−. Our results suggest that regulatory volume decrease is achieved by activation of K+ and Cl− currents. The Cl− current is responsible for the previously described depolarization and increase in insulin release induced by osmotic cell swelling. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|