Andersson T
Am J Physiol. 1983 Nov;245(5 Pt 1):C343-7. doi: 10.1152/ajpcell.1983.245.5.C343.
beta-Cell-rich pancreatic islets from ob/ob mice were loaded with 45Ca in the presence of 20 mM glucose. When the islets were transferred to a nonradioactive incubation medium depleted of Ca2+, most of the 45Ca was lost during the first 10 min of incubation irrespective of whether or not glucose was present. Isolation of subcellular fractions under conditions minimizing 45Ca redistribution disclosed that the presence of 20 mM glucose during the nonradioactive incubation increased the retention of 45Ca in the mitochondrial fraction. This effect was not reproduced by K+ depolarization of the islets. Exposure of islets to 4 mM glucose failed to affect the total content of 45Ca in the islets but increased the incorporation of the isotope into cellular organelles. These results suggest that glucose, even at concentrations below the threshold for stimulation of insulin secretion, enhances the intracellular trapping of calcium.
在20 mM葡萄糖存在的情况下，将来自ob/ob小鼠的富含β细胞的胰岛装载上45Ca。当将胰岛转移到不含Ca2+的无放射性孵育培养基中时，无论是否存在葡萄糖，大部分45Ca在孵育的最初10分钟内都会丢失。在使45Ca重新分布最小化的条件下分离亚细胞组分表明，在无放射性孵育期间存在20 mM葡萄糖会增加45Ca在线粒体组分中的保留。胰岛的K+去极化未重现这种效应。将胰岛暴露于4 mM葡萄糖未能影响胰岛中45Ca的总含量，但增加了该同位素掺入细胞器的量。这些结果表明，即使葡萄糖浓度低于刺激胰岛素分泌的阈值，它也会增强细胞内钙的捕获。
