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Voltage-gated and resting membrane currents recorded from B-cells in intact mouse pancreatic islets

Göpel, Sven LU ; Kanno, T; Barg, Sebastian LU ; Galvanovskis, Juris LU and Rorsman, Patrik LU (1999) In Journal of Physiology 521(3). p.717-728
Abstract
1. The perforated patch whole-cell configuration of the patch-clamp technique was applied to superficial cells in intact pancreatic islets. Immunostaining in combination with confocal microscopy revealed that the superficial cells consisted of 35 % insulin-secreting B-cells and 65 % non-B-cells (A- and D-cells). 2. Two types of cell, with distinct electrophysiological properties, could be functionally identified. One of these generated oscillatory electrical activity when the islet was exposed to 10 mM glucose and had the electrophysiological characteristics of isolated B-cells maintained in tissue culture. 3. The Ca2+ current recorded from B-cells in situ was 80 % larger than that of isolated B-cells. It exhibited significant (70 %)... (More)
1. The perforated patch whole-cell configuration of the patch-clamp technique was applied to superficial cells in intact pancreatic islets. Immunostaining in combination with confocal microscopy revealed that the superficial cells consisted of 35 % insulin-secreting B-cells and 65 % non-B-cells (A- and D-cells). 2. Two types of cell, with distinct electrophysiological properties, could be functionally identified. One of these generated oscillatory electrical activity when the islet was exposed to 10 mM glucose and had the electrophysiological characteristics of isolated B-cells maintained in tissue culture. 3. The Ca2+ current recorded from B-cells in situ was 80 % larger than that of isolated B-cells. It exhibited significant (70 %) inactivation during 100 ms depolarisations. The inactivation was voltage dependent and particularly prominent during depolarisations evoking the largest Ca2+ currents. 4. Voltage-dependent K+ currents were observed during depolarisations to membrane potentials above -20 mV. These currents inactivated little during a 200 ms depolarisation and were unaffected by varying the holding potential between -90 and -30 mV. 5. The maximum resting conductance in the absence of glucose, which reflects the conductance of ATP-regulated K+ (KATP) channels, amounted to approximately 4 nS. Glucose produced a concentration-dependent reduction of KATP channel conductance with half-maximal inhibition observed with 5 mM glucose. 6. Combining voltage- and current-clamp recording allowed the estimation of the gap junction conductance between different B-cells. These experiments indicated that the input conductance of the B-cell at stimulatory glucose concentrations ( approximately 1 nS) is almost entirely accounted for by coupling to neighbouring B-cells. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physiology
volume
521
issue
3
pages
717 - 728
publisher
The Physiological Society
external identifiers
  • pmid:10601501
  • scopus:0343986289
ISSN
1469-7793
language
English
LU publication?
yes
id
cc543513-aeba-4d9b-848c-6487de57e8ea (old id 1114668)
alternative location
http://jp.physoc.org/cgi/content/full/521/3/717
date added to LUP
2008-07-04 15:02:43
date last changed
2017-06-11 04:27:42
@article{cc543513-aeba-4d9b-848c-6487de57e8ea,
  abstract     = {1. The perforated patch whole-cell configuration of the patch-clamp technique was applied to superficial cells in intact pancreatic islets. Immunostaining in combination with confocal microscopy revealed that the superficial cells consisted of 35 % insulin-secreting B-cells and 65 % non-B-cells (A- and D-cells). 2. Two types of cell, with distinct electrophysiological properties, could be functionally identified. One of these generated oscillatory electrical activity when the islet was exposed to 10 mM glucose and had the electrophysiological characteristics of isolated B-cells maintained in tissue culture. 3. The Ca2+ current recorded from B-cells in situ was 80 % larger than that of isolated B-cells. It exhibited significant (70 %) inactivation during 100 ms depolarisations. The inactivation was voltage dependent and particularly prominent during depolarisations evoking the largest Ca2+ currents. 4. Voltage-dependent K+ currents were observed during depolarisations to membrane potentials above -20 mV. These currents inactivated little during a 200 ms depolarisation and were unaffected by varying the holding potential between -90 and -30 mV. 5. The maximum resting conductance in the absence of glucose, which reflects the conductance of ATP-regulated K+ (KATP) channels, amounted to approximately 4 nS. Glucose produced a concentration-dependent reduction of KATP channel conductance with half-maximal inhibition observed with 5 mM glucose. 6. Combining voltage- and current-clamp recording allowed the estimation of the gap junction conductance between different B-cells. These experiments indicated that the input conductance of the B-cell at stimulatory glucose concentrations ( approximately 1 nS) is almost entirely accounted for by coupling to neighbouring B-cells.},
  author       = {Göpel, Sven and Kanno, T and Barg, Sebastian and Galvanovskis, Juris and Rorsman, Patrik},
  issn         = {1469-7793},
  language     = {eng},
  number       = {3},
  pages        = {717--728},
  publisher    = {The Physiological Society},
  series       = {Journal of Physiology},
  title        = {Voltage-gated and resting membrane currents recorded from B-cells in intact mouse pancreatic islets},
  volume       = {521},
  year         = {1999},
}