Lund University is celebrating 350 years. Read more on lunduniversity.lu.se

Menu

Javascript is not activated in your browser. This website needs javascript activated to work properly.
You are here

A Subset of 50 Secretory Granules in Close Contact With L-Type Ca(2+) Channels Accounts for First-Phase Insulin Secretion in Mouse beta-Cells.

Author:
  • Sebastian Barg
  • Lena Eliasson
  • Erik Renström
  • Patrik Rorsman
Publishing year: 2002
Language: English
Pages: 74-82
Publication/Series: Diabetes
Volume: 51 Suppl 1
Document type: Journal article
Publisher: American Diabetes Association

Abstract english

Capacitance measurements were applied to mouse pancreatic beta-cells to elucidate the cellular mechanisms underlying biphasic insulin secretion. We report here that only <50 of the beta-cell's >10,000 granules are immediately available for release. The releasable granules tightly associate with the voltage-gated alpha(1C) Ca(2+) channels, and it is proposed that the release of these granules accounts for first-phase insulin secretion. Subsequent replenishment of the releasable pool by priming of previously nonreleasable granules is required for second-phase insulin secretion. The latter reaction depends on intragranular acidification due to the concerted action of granular bafilomycin-sensitive v-type H(+)-ATPase and 4,4-diisothiocyanostilbene-2,2-disulfonate--blockable ClC-3 Cl(-) channels. Lowering the cytoplasmic ATP/ADP ratio prevents granule acidification, granule priming, and refilling of the releasable pool. The latter finding provides an explanation to the transient nature of insulin secretion elicited by, for example, high extracellular K(+) in the absence of metabolizable fuels.

Keywords

  • Endocrinology and Diabetes

Other

Published
  • Islet cell physiology
  • Islet cell exocytosis
  • Islet patophysiology
  • ISSN: 1939-327X
Erik Renström
E-mail: erik [dot] renstrom [at] med [dot] lu [dot] se

Deputy head of department

Department of Clinical Sciences, Malmö

+46 40 39 11 57

+46 40 39 11 57

Principal investigator

Islet patophysiology

+46 40 39 11 57

+46 40 39 11 57

20-3-308

33

Lund University Diabetes Centre, CRC, SUS Malmö, Entrance 72, House 91:12. SE-205 02 Malmö. Telephone: +46 40 39 10 00