uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets.
2000 (English)In: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 528, no Pt 3, 497-507 p.Article in journal (Refereed) Published
Abstract [en]

The perforated patch whole-cell configuration of the patch-clamp technique was applied to superficial cells in intact mouse pancreatic islets. Three types of electrical activity were observed corresponding to alpha-, beta- and delta-cells. The delta-cells were electrically active in the presence of glucose but lacked the oscillatory pattern seen in the beta-cells. By contrast, the alpha-cells were electrically silent at high glucose concentrations but action potentials could be elicited by removal of the sugar. Both alpha- and beta-cells contained transient voltage-activated K+ currents. In the delta-cells, the K+ currents activated above -20 mV and were completely blocked by TEA (20 mM). The alpha-cells differed from the delta-cells in possessing a TEA-resistant K+ current activating already at -40 mV. Immunocytochemistry revealed the presence of Kv3.4 channels in delta-cells and TEA-resistant Kv4.3 channels in alpha-cells. Thus the presence of a transient TEA-resistant current can be used to functionally separate the delta- and alpha-cells. A TTX-sensitive Na+ current developed in delta-cells during depolarisations beyond -30 mV and reached a peak amplitude of 350 pA. Steady-state inactivation of this current was half-maximal at -28 mV. The delta-cells were also equipped with a sustained Ca2+ current that activated above -30 mV and reached a peak of 60 pA when measured at 2.6 mM extracellular Ca2+. A tolbutamide-sensitive KATP channel conductance was observed in delta-cells exposed to glucose-free medium. Addition of tolbutamide (0.1 mM) depolarised the delta-cell and evoked electrical activity. We propose that the KATP channels in delta-cells serve the same function as in the beta-cell and couple an elevation of the blood glucose concentration to stimulation of hormone release.

Place, publisher, year, edition, pages
2000. Vol. 528, no Pt 3, 497-507 p.
National Category
Medical and Health Sciences
URN: urn:nbn:se:uu:diva-161878PubMedID: 11060127OAI: oai:DiVA.org:uu-161878DiVA: diva2:457779
Available from: 2011-11-19 Created: 2011-11-19 Last updated: 2011-11-19

Open Access in DiVA

No full text


Search in DiVA

By author/editor
Barg, S
In the same journal
Journal of Physiology
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 238 hits
ReferencesLink to record
Permanent link

Direct link