Glucose-stimulated and La3+-nondisplaceable Ca2+ pool in pancreatic islets.
PMID 190894 · The American journal of physiology · 1977 · DOI 10.1152/ajpendo.1977.232.2.E114
Authors: G D Bloom; B Hellman; J Sehlin; I Täljedal
Abstract
To study intracellular pools of calcium tissue specimens from noninbred ob/ob mice were labeled with 45Ca2+ and subsequently washed with La3+. D-glucose, 20 mM, enhanced the labeling of the La3+-nondisplaceable calcium in pancreatic islets but not in pieces of exocrine pancreas or liver. The disappearance of 45Ca2+ from labeled islets was accelerated by the ionophore, X-537A, but not by dibutyryl cyclic AMP, theophylline, or pentobarbital. On fractionation of 45Ca2+-labeled islets, the greatest radioactivity per unit of protein occured in a fraction rich in insulin secretory granules. The radioactivity of this fraction was higher after the islets had been loaded with 45Ca2+ in the presence of 20 mM glucose as compared to 3 mM glucose. It is concluded that the secretory granules make up a considerable part of the glucose-sensitive calcium store in the beta-cells.
Animals; Bucladesine; Calcium; Glucose; Islets of Langerhans; Lanthanum; Lasalocid; Liver; Mice; Mitochondria; Pancreas; Pentobarbital; Stimulation, Chemical; Subcellular Fractions; Theophylline
Cite
G D Bloom; B Hellman; J Sehlin; I Täljedal. Glucose-stimulated and La3+-nondisplaceable Ca2+ pool in pancreatic islets. The American journal of physiology (1977). PMID 190894. DOI 10.1152/ajpendo.1977.232.2.E114.