Somatostatin induces hyperpolarization in pancreatic islet α cells by activating a G protein‐gated K+ channel
- 12 February 1999
- journal article
- Published by Wiley in FEBS Letters
- Vol. 444 (2-3) , 265-269
- https://doi.org/10.1016/s0014-5793(99)00076-9
Abstract
Somatostatin inhibits glucagon-secretion from pancreatic alpha cells but its underlying mechanism is unknown. In mouse alpha cells, we found that somatostatin induced prominent hyperpolarization by activating a K+ channel, which was unaffected by tolbutamide but prevented by pre-treating the cells with pertussis toxin. The K+ channel was activated by intracellular GTP (with somatostatin), GTPgammaS or Gbetagamma subunits. It was thus identified as a G protein-gated K+ (K(G)) channel. RT-PCR and immunohistochemical analyses suggested the K(G) channel to be composed of Kir3.2c and Kir3.4. This study identified a novel ionic mechanism involved in somatostatin-inhibition of glucagon-secretion from pancreatic alpha cells.Keywords
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