Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets.
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...
| Main Authors: | , , , |
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| Format: | Journal article |
| Language: | English |
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2000
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| _version_ | 1797094196693172224 |
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| author | Göpel, S Kanno, T Barg, S Rorsman, P |
| author_facet | Göpel, S Kanno, T Barg, S Rorsman, P |
| author_sort | Göpel, S |
| collection | OXFORD |
| description | 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. |
| first_indexed | 2024-03-07T04:10:43Z |
| format | Journal article |
| id | oxford-uuid:c7bc20bb-f96f-49a5-84f1-29f233bdf447 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T04:10:43Z |
| publishDate | 2000 |
| record_format | dspace |
| spelling | oxford-uuid:c7bc20bb-f96f-49a5-84f1-29f233bdf4472022-03-27T06:47:15ZPatch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c7bc20bb-f96f-49a5-84f1-29f233bdf447EnglishSymplectic Elements at Oxford2000Göpel, SKanno, TBarg, SRorsman, PThe 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. |
| spellingShingle | Göpel, S Kanno, T Barg, S Rorsman, P Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title | Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title_full | Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title_fullStr | Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title_full_unstemmed | Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title_short | Patch-clamp characterisation of somatostatin-secreting -cells in intact mouse pancreatic islets. |
| title_sort | patch clamp characterisation of somatostatin secreting cells in intact mouse pancreatic islets |
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