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Adrenaline stimulates glucagon secretion in pancreatic A-cells by increasing the Ca2+ current and the number of granules close to the L-type Ca2+ channels

Gromada, J; Bokvist, K; Ding, W G; Barg, Sebastian LU ; Buschard, K; Renström, Erik LU and Rorsman, Patrik LU (1997) In Journal of General Physiology 110(3). p.217-228
Abstract
We have monitored electrical activity, voltage-gated Ca2+ currents, and exocytosis in single rat glucagon-secreting pancreatic A-cells. The A-cells were electrically excitable and generated spontaneous Na+- and Ca2+-dependent action potentials. Under basal conditions, exocytosis was tightly linked to Ca2+ influx through omega-conotoxin-GVIA-sensitive (N-type) Ca2+ channels. Stimulation of the A-cells with adrenaline (via beta-adrenergic receptors) or forskolin produced a greater than fourfold PKA-dependent potentiation of depolarization-evoked exocytosis. This enhancement of exocytosis was due to a 50% enhancement of Ca2+ influx through L-type Ca2+ channels, an effect that accounted for <30% of the total stimulatory action. The... (More)
We have monitored electrical activity, voltage-gated Ca2+ currents, and exocytosis in single rat glucagon-secreting pancreatic A-cells. The A-cells were electrically excitable and generated spontaneous Na+- and Ca2+-dependent action potentials. Under basal conditions, exocytosis was tightly linked to Ca2+ influx through omega-conotoxin-GVIA-sensitive (N-type) Ca2+ channels. Stimulation of the A-cells with adrenaline (via beta-adrenergic receptors) or forskolin produced a greater than fourfold PKA-dependent potentiation of depolarization-evoked exocytosis. This enhancement of exocytosis was due to a 50% enhancement of Ca2+ influx through L-type Ca2+ channels, an effect that accounted for <30% of the total stimulatory action. The remaining 70% of the stimulation was attributable to an acceleration of granule mobilization resulting in a fivefold increase in the number of readily releasable granules near the L-type Ca2+ channels. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
glucagon, Ca2+, secretion
in
Journal of General Physiology
volume
110
issue
3
pages
217 - 228
publisher
Rockefeller Institute for Medical Research
external identifiers
  • pmid:9276750
  • scopus:0030967933
ISSN
0022-1295
language
English
LU publication?
no
id
ad7f60ac-295c-4a20-9607-523430576791 (old id 1111594)
alternative location
http://www.jgp.org/cgi/content/full/110/3/217
date added to LUP
2008-07-18 08:51:08
date last changed
2017-08-06 04:26:49
@article{ad7f60ac-295c-4a20-9607-523430576791,
  abstract     = {We have monitored electrical activity, voltage-gated Ca2+ currents, and exocytosis in single rat glucagon-secreting pancreatic A-cells. The A-cells were electrically excitable and generated spontaneous Na+- and Ca2+-dependent action potentials. Under basal conditions, exocytosis was tightly linked to Ca2+ influx through omega-conotoxin-GVIA-sensitive (N-type) Ca2+ channels. Stimulation of the A-cells with adrenaline (via beta-adrenergic receptors) or forskolin produced a greater than fourfold PKA-dependent potentiation of depolarization-evoked exocytosis. This enhancement of exocytosis was due to a 50% enhancement of Ca2+ influx through L-type Ca2+ channels, an effect that accounted for &lt;30% of the total stimulatory action. The remaining 70% of the stimulation was attributable to an acceleration of granule mobilization resulting in a fivefold increase in the number of readily releasable granules near the L-type Ca2+ channels.},
  author       = {Gromada, J and Bokvist, K and Ding, W G and Barg, Sebastian and Buschard, K and Renström, Erik and Rorsman, Patrik},
  issn         = {0022-1295},
  keyword      = {glucagon,Ca2+,secretion},
  language     = {eng},
  number       = {3},
  pages        = {217--228},
  publisher    = {Rockefeller Institute for Medical Research},
  series       = {Journal of General Physiology},
  title        = {Adrenaline stimulates glucagon secretion in pancreatic A-cells by increasing the Ca2+ current and the number of granules close to the L-type Ca2+ channels},
  volume       = {110},
  year         = {1997},
}