Hormonal activation of single K+ channels via internal messenger in isolated pancreatic acinar cells.
The mechanism underlying hormonal activation of potassium channels was investigated in pig pancreatic acinar cells by patch-clamp single-channel and whole-cell current recordings. It was shown directly that a peptide hormone belonging to the cholecystokinin-gastrin family, CCK5, can activate single voltage-sensitive potassium channels which can be blocked by tetraethylammonium. The single-channel currents were recorded from electrically isolated cell-attached membrane patches to which the hormone had no access and the activation must therefore involve an intracellular messenger. The hormonal response requires external Ca2+ in the isolated membrane-patch area indicating that calcium gating is not directly linked to hormone-receptor interaction.
K
K
Suzuki
C C
CC
Petersen
O H
OH
Petersen
D000818:Animals; D002766:Cholecystokinin / Q000031:analogs & derivatives* / Q000494:pharmacology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects; D010179:Pancreas / Q000166:cytology / Q000502:physiology*; D010418:Pentagastrin / Q000031:analogs & derivatives* / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D013552:Swine
D007473:Ion Channels; C037823:cholecystokinin 5-pentagastrin; D002766:Cholecystokinin; D010418:Pentagastrin; D011188:Potassium