Calcium and secretagogues-induced conductances in rat exocrine pancreas.
The electrical properties of single acinar cells isolated from rat pancreas were studied with the whole-cell tight-seal recording method. Under resting conditions, the relative permeabilities of Cl and K were PCl/PK approximately equal to 3. At 1 microM internal calcium, a Ca and voltage-dependent Cl conductance was activated. At 10 microM internal calcium, the major conductance was selective for cations. It was not voltage-dependent. Acetylcholine and cholecystokinin induced an increase of internal Ca which in turn activated either only a Cl conductance or both Cl and cationic conductances. The secretagogue-induced conductance was increased to a variable extent by depolarisation. The absence of K channels activated by internal calcium indicates that, in pancreatic acinar cells, the mechanism of fluid secretion differs from that observed in other exocrine glands.
D000109:Acetylcholine / Q000494:pharmacology*; D000200:Action Potentials / Q000187:drug effects*; D000818:Animals; D000838:Anions / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D002412:Cations / Q000378:metabolism; D002712:Chlorides / Q000494:pharmacology; D002766:Cholecystokinin / Q000494:pharmacology*; D007473:Ion Channels / Q000502:physiology; D008564:Membrane Potentials / Q000187:drug effects*; D010179:Pancreas / Q000166:cytology / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats
D000838:Anions; D002412:Cations; D002712:Chlorides; D007473:Ion Channels; D002766:Cholecystokinin; D000109:Acetylcholine; D011188:Potassium; D002118:Calcium