A Subset of 50 Secretory Granules in Close Contact With L-Type Ca(2+) Channels Accounts for First-Phase Insulin Secretion in Mouse beta-Cells.
Capacitance measurements were applied to mouse pancreatic beta-cells to elucidate the cellular mechanisms underlying biphasic insulin secretion. We report here that only <50 of the beta-cell's >10,000 granules are immediately available for release. The releasable granules tightly associate with the voltage-gated alpha(1C) Ca(2+) channels, and it is proposed that the release of these granules accou
