Foster M C, Leapman R D, Li M X, Atwater I
Department of Anesthesiology, School of Medicine, State University of New York, Stony Brook 11794-8480.
Biophys J. 1993 Feb;64(2):525-32. doi: 10.1016/S0006-3495(93)81397-3.
We have characterized, by electron probe microanalysis, rapidly frozen cultured rat islets at the level of individual secretory granules. Elemental analysis of thin, dried cryosections showed that beta granules could be distinguished by high Zn, Ca, and S, whereas non-beta (mainly alpha) granules contained elevated P and Mg. Although a single granule type predominated in a particular cell, some rebel granules were found in A cells that had the compositional fingerprint of B cell granules. Zn, which was found in millimolar concentrations in B cell granules, was considered a marker for the insulin storage complex. The data indicate that non-B islet cells in the adult pancreas may produce insulin-containing organelles and that, when glucagon and insulin are coexpressed, these hormones are packaged in separate granules.
我们通过电子探针显微分析，在单个分泌颗粒水平对快速冷冻的培养大鼠胰岛进行了表征。对薄的干燥冷冻切片进行元素分析表明，β颗粒可通过高含量的锌、钙和硫来区分，而非β（主要是α）颗粒则含有较高的磷和镁。尽管在特定细胞中单一颗粒类型占主导，但在具有B细胞颗粒组成特征的A细胞中发现了一些“叛逆”颗粒。在B细胞颗粒中以毫摩尔浓度存在的锌被认为是胰岛素储存复合物的标志物。数据表明，成年胰腺中的非B胰岛细胞可能产生含胰岛素的细胞器，并且当胰高血糖素和胰岛素共表达时，这些激素被包装在不同的颗粒中。
