Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets
(2000) In Journal of Physiology 528(3). p.497-507- Abstract
- 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... (More)
- 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. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1117036
- author
- Göpel, Sven LU ; Kanno, T ; Barg, Sebastian LU and Rorsman, Patrik LU
- organization
- publishing date
- 2000
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Physiology
- volume
- 528
- issue
- 3
- pages
- 497 - 507
- publisher
- The Physiological Society
- external identifiers
-
- pmid:11060127
- ISSN
- 1469-7793
- language
- English
- LU publication?
- yes
- id
- 1eb7eeec-8e94-426f-95b3-a6b26c147374 (old id 1117036)
- alternative location
- http://jp.physoc.org/cgi/content/full/528/3/497
- date added to LUP
- 2016-04-01 16:20:31
- date last changed
- 2018-11-21 20:40:39
@article{1eb7eeec-8e94-426f-95b3-a6b26c147374, abstract = {{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.}}, author = {{Göpel, Sven and Kanno, T and Barg, Sebastian and Rorsman, Patrik}}, issn = {{1469-7793}}, language = {{eng}}, number = {{3}}, pages = {{497--507}}, publisher = {{The Physiological Society}}, series = {{Journal of Physiology}}, title = {{Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets}}, url = {{http://jp.physoc.org/cgi/content/full/528/3/497}}, volume = {{528}}, year = {{2000}}, }