Intracellular Localization of Calcium in Pancreatic B Cells in Relation to Insulin Secretion by the Perfused ob/ob Mouse Pancreas*

Publisher Website
Google Scholar
Abstract
Changes in the distribution of intracellular Ca in .beta.-cells from the perfused ob/ob mouse pancreas in relation to the secretory state of the .beta.-cell were followed using the pyroantimonate technique for Ca precipitation. At the internal surface of the .beta.-cell membrane a highly mobile reservoir of Ca was mobilized during the first 1-3 min of stimulation of the .beta.-cells by glucose as well as by tolbutamide resulting in an increased Ca precipitation in the cytoplasm. During prolonged stimulation of insulin secretion by glucose the Ca precipitation along the internal surface of the .beta.-cell membrane was restored. Concomitantly Ca deposits in the secretory granules and to a lesser extent in the mitochondria increased. Tolbutamide neither restored in the membrane-bound pool nor increased the Ca uptake of the secretory granules but decreased mitochondrial Ca. Apparently the cytoplasmic increase of Ca primarily results from intracellular redistribution.

This publication has 3 references indexed in Scilit: