Ion channels, electrical activity and insulin secretion.
|Abstract||The insulin-secreting pancreatic beta cell is electrically excitable and changes in the membrane potential play an important role in coupling the metabolism of glucose (and other nutrient secretagogues) to the discharge of the insulin-containing granule. The application of the patch-clamp technique, which permits the recordings of the minute currents associated with the opening of individual ion channels, to pancreatic islet cells has revolutioni ... [truncated at 450 characters in length]|
|Author||Rorsman, P; Bokvist, K; Ammälä, C; et al|
Stimulus-secretion coupling in pancreatic beta cells.
|Abstract||Insulin secretion is triggered by a rise in the intracellular Ca2+ concentration that results from the activation of voltage-gated Ca2+ channels in the beta-cell plasma membrane. Multiple types of beta-cell Ca2+ channel have been identified in both electrophysiological and molecular biological studies, but it appears that the L-type Ca2+ channel plays a dominant role in regulating Ca2+ influx. Activity of this channel is potentiated by protein ki ... [truncated at 450 characters in length]|
|Author||Ashcroft, FM; Proks, P; Smith, PA; et al|
Regulation of glucagon release in mouse -cells by KATP channels and inactivation of TTX-sensitive Na+ channels.
|Abstract||The perforated patch whole-cell configuration of the patch-clamp technique was applied to superficial glucagon-secreting alpha-cells in intact mouse pancreatic islets. alpha-cells were distinguished from the beta- and delta-cells by the presence of a large TTX-blockable Na+ current, a TEA-resistant transient K+ current sensitive to 4-AP (A-current) and the presence of two kinetically separable Ca2+ current components corresponding to low- (T-type ... [truncated at 450 characters in length]|
|Author||Göpel, SO; Kanno, T; Barg, S; et al|
Membrane potential-dependent inactivation of voltage-gated ion channels in alpha-cells inhibits glucagon secretion from human islets.
|Abstract||To document the properties of the voltage-gated ion channels in human pancreatic alpha-cells and their role in glucagon release.|
|Author||Ramracheya, R; Ward, C; Shigeto, M; et al|
Glucose inhibition of glucagon secretion from rat alpha-cells is mediated by GABA released from neighboring beta-cells.
|Abstract||gamma-Aminobutyric acid (GABA) has been proposed to function as a paracrine signaling molecule in islets of Langerhans. We have shown that rat beta-cells release GABA by Ca(2+)-dependent exocytosis of synaptic-like microvesicles. Here we demonstrate that GABA thus released can diffuse over sufficient distances within the islet interstitium to activate GABA(A) receptors in neighboring cells. Confocal immunocytochemistry revealed the presence of GA ... [truncated at 450 characters in length]|
|Author||Wendt, A; Birnir, B; Buschard, K; et al|