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Co-localization of L-type Ca2+ channels and insulin-containing secretory granules and its significance for the initiation of exocytosis in mouse pancreatic B-cells

Bokvist, K; Eliasson, Lena LU ; Ammala, C; Renström, Erik LU and Rorsman, Patrik LU (1995) In EMBO Journal 14(1). p.50-57
Abstract
We have monitored L-type Ca2+ channel activity, local cytoplasmic Ca2+ transients, the distribution of insulin-containing secretory granules and exocytosis in individual mouse pancreatic B-cells. Subsequent to the opening of the Ca2+ channels, exocytosis is initiated with a latency < 100 ms. The entry of Ca2+ that precedes exocytosis is unevenly distributed over the cell and is concentrated to the region with the highest density of secretory granules. In this region, the cytoplasmic Ca2+ concentration is 5- to 10-fold higher than in the remainder of the cell reaching concentrations of several micromolar. Single-channel recordings confirm that the L-type Ca2+ channels are clustered in the part of the cell containing the secretory... (More)
We have monitored L-type Ca2+ channel activity, local cytoplasmic Ca2+ transients, the distribution of insulin-containing secretory granules and exocytosis in individual mouse pancreatic B-cells. Subsequent to the opening of the Ca2+ channels, exocytosis is initiated with a latency < 100 ms. The entry of Ca2+ that precedes exocytosis is unevenly distributed over the cell and is concentrated to the region with the highest density of secretory granules. In this region, the cytoplasmic Ca2+ concentration is 5- to 10-fold higher than in the remainder of the cell reaching concentrations of several micromolar. Single-channel recordings confirm that the L-type Ca2+ channels are clustered in the part of the cell containing the secretory granules. This arrangement, which is obviously reminiscent of the 'active zones' in nerve terminals, can be envisaged as being favourable to the B-cell as it ensures that the Ca2+ transient is maximal and restricted to the part of the cell where it is required to rapidly initiate exocytosis whilst at the same time minimizing the expenditure of metabolic energy to subsequently restore the resting Ca2+ concentration. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
in
EMBO Journal
volume
14
issue
1
pages
50 - 57
publisher
Oxford University Press
external identifiers
  • pmid:7828595
  • scopus:0028984692
ISSN
1460-2075
language
English
LU publication?
yes
id
48f131b2-6b37-405e-9771-6a3d87d90890 (old id 1108853)
alternative location
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=398051
date added to LUP
2008-07-24 17:12:57
date last changed
2017-08-20 04:20:53
@article{48f131b2-6b37-405e-9771-6a3d87d90890,
  abstract     = {We have monitored L-type Ca2+ channel activity, local cytoplasmic Ca2+ transients, the distribution of insulin-containing secretory granules and exocytosis in individual mouse pancreatic B-cells. Subsequent to the opening of the Ca2+ channels, exocytosis is initiated with a latency &lt; 100 ms. The entry of Ca2+ that precedes exocytosis is unevenly distributed over the cell and is concentrated to the region with the highest density of secretory granules. In this region, the cytoplasmic Ca2+ concentration is 5- to 10-fold higher than in the remainder of the cell reaching concentrations of several micromolar. Single-channel recordings confirm that the L-type Ca2+ channels are clustered in the part of the cell containing the secretory granules. This arrangement, which is obviously reminiscent of the 'active zones' in nerve terminals, can be envisaged as being favourable to the B-cell as it ensures that the Ca2+ transient is maximal and restricted to the part of the cell where it is required to rapidly initiate exocytosis whilst at the same time minimizing the expenditure of metabolic energy to subsequently restore the resting Ca2+ concentration.},
  author       = {Bokvist, K and Eliasson, Lena and Ammala, C and Renström, Erik and Rorsman, Patrik},
  issn         = {1460-2075},
  language     = {eng},
  number       = {1},
  pages        = {50--57},
  publisher    = {Oxford University Press},
  series       = {EMBO Journal},
  title        = {Co-localization of L-type Ca2+ channels and insulin-containing secretory granules and its significance for the initiation of exocytosis in mouse pancreatic B-cells},
  volume       = {14},
  year         = {1995},
}