Simultaneous recordings of glucose dependent electrical activity and ATP-regulated K(+)-currents in isolated mouse pancreatic beta-cells.
Membrane potential and membrane currents were recorded from single mouse pancreatic beta-cells using the perforated patch whole-cell recording technique at 30 degrees C. Single beta-cells maintained in primary tissue culture exhibited glucose-dependent electrical activity similar to that reported for freshly isolated intact islets. The resting input conductance (5.1 +/- 0.9 nS) was determined by ATP-regulated K+ (KATP) channels as it was blocked by 1 mM tolbutamide. 8 mM glucose decreased the input conductance by 80%. The input conductance at -70 mV was of a similar value during the plateau phase and during the silent phase of electrical activity in 8 mM glucose. This suggests that oscillations of KATP channel activity do not underlie the slow waves.
University Laboratory of Physiology, Oxford University, England.
P A
PA
Smith
F M
FM
Ashcroft
P
P
Rorsman
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004553:Electric Conductivity; D005947:Glucose / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D014044:Tolbutamide / Q000494:pharmacology
D015221:Potassium Channels; D000255:Adenosine Triphosphate; D014044:Tolbutamide; D005947:Glucose