Co-localization of L-type Ca2+ channels and insulin-containing secretory granules and its significance for the initiation of exocytosis in mouse pancreatic B-cells
We have monitored L-type Ca2+ channel activity, local cytoplasmic Ca2+ transients, the distribution of insulin-containing secretory granules and exocytosis in individual mouse pancreatic B-cells. Subsequent to the opening of the Ca2+ channels, exocytosis is initiated with a latency < 100 ms. The entry of Ca2+ that precedes exocytosis is unevenly distributed over the cell and is concentrated to the