Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells.
Somatostatin hyperpolarized rat pancreatic alpha-cells and inhibited spontaneous electrical activity by activating a low-conductance K+ channel (0.9 pS with physiological ionic gradients). This channel was insensitive to tolbutamide (a blocker of ATP-sensitive K+ channels) and apamin (an inhibitor o...
| Auteurs principaux: | , , , , , , |
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| Format: | Journal article |
| Langue: | English |
| Publié: |
2001
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| _version_ | 1826289912373051392 |
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| author | Gromada, J Høy, M Olsen, H Gotfredsen, C Buschard, K Rorsman, P Bokvist, K |
| author_facet | Gromada, J Høy, M Olsen, H Gotfredsen, C Buschard, K Rorsman, P Bokvist, K |
| author_sort | Gromada, J |
| collection | OXFORD |
| description | Somatostatin hyperpolarized rat pancreatic alpha-cells and inhibited spontaneous electrical activity by activating a low-conductance K+ channel (0.9 pS with physiological ionic gradients). This channel was insensitive to tolbutamide (a blocker of ATP-sensitive K+ channels) and apamin (an inhibitor of small-conductance Ca(2+)-activated K+ channels). Channel activation was prevented by pre-treating the cells with pertussis toxin, indicating the involvement of G-proteins. A direct interaction between an inhibitory G-protein and the somatostatin-activated K+ channel is suggested by the finding that intracellular application of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma-S) and the G beta gamma subunit of G-proteins resulted in a transient stimulation of the current. Activation of the K+ current by somatostatin was inhibited by intracellular dialysis with specific antibodies to Gi1/2 and was not seen in cells treated with antisense oligonucleotides against G-proteins of the subtype Gi2. We conclude that somatostatin suppresses alpha-cell electrical activity by a Gi2-protein-dependent mechanism, which culminates in the activation of a sulphonylurea- and apamin-insensitive low-conductance K+ channel. |
| first_indexed | 2024-03-07T02:36:08Z |
| format | Journal article |
| id | oxford-uuid:a8dc315b-9d6b-4147-9d4c-9b06aa6e009d |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T02:36:08Z |
| publishDate | 2001 |
| record_format | dspace |
| spelling | oxford-uuid:a8dc315b-9d6b-4147-9d4c-9b06aa6e009d2022-03-27T03:04:27ZGi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:a8dc315b-9d6b-4147-9d4c-9b06aa6e009dEnglishSymplectic Elements at Oxford2001Gromada, JHøy, MOlsen, HGotfredsen, CBuschard, KRorsman, PBokvist, KSomatostatin hyperpolarized rat pancreatic alpha-cells and inhibited spontaneous electrical activity by activating a low-conductance K+ channel (0.9 pS with physiological ionic gradients). This channel was insensitive to tolbutamide (a blocker of ATP-sensitive K+ channels) and apamin (an inhibitor of small-conductance Ca(2+)-activated K+ channels). Channel activation was prevented by pre-treating the cells with pertussis toxin, indicating the involvement of G-proteins. A direct interaction between an inhibitory G-protein and the somatostatin-activated K+ channel is suggested by the finding that intracellular application of guanosine 5'-O-(3-thiotriphosphate) (GTP gamma-S) and the G beta gamma subunit of G-proteins resulted in a transient stimulation of the current. Activation of the K+ current by somatostatin was inhibited by intracellular dialysis with specific antibodies to Gi1/2 and was not seen in cells treated with antisense oligonucleotides against G-proteins of the subtype Gi2. We conclude that somatostatin suppresses alpha-cell electrical activity by a Gi2-protein-dependent mechanism, which culminates in the activation of a sulphonylurea- and apamin-insensitive low-conductance K+ channel. |
| spellingShingle | Gromada, J Høy, M Olsen, H Gotfredsen, C Buschard, K Rorsman, P Bokvist, K Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title | Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title_full | Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title_fullStr | Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title_full_unstemmed | Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title_short | Gi2 proteins couple somatostatin receptors to low-conductance K+ channels in rat pancreatic alpha-cells. |
| title_sort | gi2 proteins couple somatostatin receptors to low conductance k channels in rat pancreatic alpha cells |
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