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Activation of Ca(2+)-dependent K(+) channels contributes to rhythmic firing of action potentials in mouse pancreatic beta cells

Göpel, Sven LU ; Kanno, Takahiro; Barg, Sebastian LU ; Eliasson, Lena LU ; Galvanovskis, Juris LU ; Renström, Erik LU and Rorsman, Patrik LU (1999) In Journal of General Physiology 114(6). p.759-770
Abstract
We have applied the perforated patch whole-cell technique to beta cells within intact pancreatic islets to identify the current underlying the glucose-induced rhythmic firing of action potentials. Trains of depolarizations (to simulate glucose-induced electrical activity) resulted in the gradual (time constant: 2.3 s) development of a small (<0.8 nS) K(+) conductance. The current was dependent on Ca(2+) influx but unaffected by apamin and charybdotoxin, two blockers of Ca(2+)-activated K(+) channels, and was insensitive to tolbutamide (a blocker of ATP-regulated K(+) channels) but partially (>60%) blocked by high (10-20 mM) concentrations of tetraethylammonium. Upon cessation of electrical stimulation, the current deactivated... (More)
We have applied the perforated patch whole-cell technique to beta cells within intact pancreatic islets to identify the current underlying the glucose-induced rhythmic firing of action potentials. Trains of depolarizations (to simulate glucose-induced electrical activity) resulted in the gradual (time constant: 2.3 s) development of a small (<0.8 nS) K(+) conductance. The current was dependent on Ca(2+) influx but unaffected by apamin and charybdotoxin, two blockers of Ca(2+)-activated K(+) channels, and was insensitive to tolbutamide (a blocker of ATP-regulated K(+) channels) but partially (>60%) blocked by high (10-20 mM) concentrations of tetraethylammonium. Upon cessation of electrical stimulation, the current deactivated exponentially with a time constant of 6.5 s. This is similar to the interval between two successive bursts of action potentials. We propose that this Ca(2+)-activated K(+) current plays an important role in the generation of oscillatory electrical activity in the beta cell. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Ca2+-activated K+ channel, pancreas, insulin, Ca2+, membrane potential
in
Journal of General Physiology
volume
114
issue
6
pages
759 - 770
publisher
Rockefeller Institute for Medical Research
external identifiers
  • pmid:10578013
ISSN
0022-1295
language
English
LU publication?
yes
id
ff0d3911-665e-49de-ab89-e6c91157a3da (old id 1114673)
alternative location
http://www.jgp.org/cgi/content/full/114/6/759
date added to LUP
2008-07-04 15:08:00
date last changed
2016-04-16 03:58:18
@article{ff0d3911-665e-49de-ab89-e6c91157a3da,
  abstract     = {We have applied the perforated patch whole-cell technique to beta cells within intact pancreatic islets to identify the current underlying the glucose-induced rhythmic firing of action potentials. Trains of depolarizations (to simulate glucose-induced electrical activity) resulted in the gradual (time constant: 2.3 s) development of a small (&lt;0.8 nS) K(+) conductance. The current was dependent on Ca(2+) influx but unaffected by apamin and charybdotoxin, two blockers of Ca(2+)-activated K(+) channels, and was insensitive to tolbutamide (a blocker of ATP-regulated K(+) channels) but partially (&gt;60%) blocked by high (10-20 mM) concentrations of tetraethylammonium. Upon cessation of electrical stimulation, the current deactivated exponentially with a time constant of 6.5 s. This is similar to the interval between two successive bursts of action potentials. We propose that this Ca(2+)-activated K(+) current plays an important role in the generation of oscillatory electrical activity in the beta cell.},
  author       = {Göpel, Sven and Kanno, Takahiro and Barg, Sebastian and Eliasson, Lena and Galvanovskis, Juris and Renström, Erik and Rorsman, Patrik},
  issn         = {0022-1295},
  keyword      = {Ca2+-activated K+ channel,pancreas,insulin,Ca2+,membrane potential},
  language     = {eng},
  number       = {6},
  pages        = {759--770},
  publisher    = {Rockefeller Institute for Medical Research},
  series       = {Journal of General Physiology},
  title        = {Activation of Ca(2+)-dependent K(+) channels contributes to rhythmic firing of action potentials in mouse pancreatic beta cells},
  volume       = {114},
  year         = {1999},
}