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Endocrine Pancreas - Beta Cell

Pancreatic Endocrine Tissue Comprises 1%, or Less, of the Pancreas and Is Organized as Clusters of Cells Dispersed throughout the Exocrine Pancreas. Glucose-dependent insulin secretion from β cells, by analogy to excitation–contraction coupling in muscle, is referred to as stimulus-secretion coupling.

1. Glucose stimulation elicits depolarisation of the cell membrane and electrical activity in β cells.
2. Opens calcium ion (Ca ²⁺) channels in the membrane that respond to changes in voltage—voltage-dependent calcium channels (VDCCs)
3. Allow Ca ²⁺ entry and action potential firing.
4. Ca ²⁺ acts on the exocytotic machinery to stimulate fusion of insulin-containing vesicles with the plasma membrane.
5. Vesicle secretion into the bloodstream.

(text modified from original reference)

Reference

<pubmed>16464129</pubmed>| PLoS Biol.

Citation: MacDonald PE, Rorsman P (2006) Oscillations, Intercellular Coupling, and Insulin Secretion in Pancreatic β Cells. PLoS Biol 4(2): e49. doi:10.1371/journal.pbio.0040049

Published: February 14, 2006

Copyright: © 2006 MacDonald and Rorsman. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.