ANALYTICAL ELECTRON MICROSCOPY OF PANCREATIC ISLET OF LANGERHANS

单个分泌颗粒的组成已经用 静息或非刺激胰腺的电子探针X射线显微分析 胰岛细胞。胶原酶消化法分离成人胰岛 大鼠，在37℃的培养液中孵育2-3小时 在5.6 mmol/l葡萄糖存在下，冷冻，冷冻切片。冰冻切片 经冷冻干燥后在电子显微镜下进行分析。颗粒剂在 一些电池含有高水平的硫和锌，可归因于 β细胞中的胰岛素储存细胞器。其他细胞中的颗粒 含硫量低，没有检测到锌，可归因于 阿尔法细胞中含有胰升糖素的分泌细胞器。磷 α细胞和β细胞颗粒中的含量都很高，与 其他观察结果表明，ATP主要集中在分泌颗粒中。颗粒剂 钙浓度通常在10到80毫摩尔/千克干重之间变化 在一个贝塔细胞中。贝塔颗粒的锌含量约为30% 干重和硫含量约为400 mmol/kg干重 重量，与锌-胰岛素的其他数据在数量上一致 仓储综合体。有趣的是，一些含有成分的颗粒 在非β细胞中发现有β颗粒的特征。

The compositions of individual secretory granules have been measured using electron probe x-ray microanalysis in resting, or unstimulated, pancreatic islet cells. Islets were isolated by collagenase digestion from adult rats, incubated for 2 to 3 hours in culture medium at 37 degrees C in the presence of 5.6 mmol/1 glucose, frozen, and cryosectioned. Cryosections were freeze-dried and analyzed in the electron microscope. Granules in some cells contained high levels of sulfur and zinc, attributable to insulin storage organelles in beta cells. Granules in other cells contained low levels of sulfur and no detectable zinc, attributable to glucagon-containing secretory organelles in alpha cells. Phosphorus content was high in granules of both alpha and beta cells, consistent with other observations that ATP is concentrated in secretory granules. Granule calcium concentrations typically varied from 10 to 80 mmol/kg dry weight within a beta cell. Zinc content of beta granules was approximately 30 mmol/kg dry weight and sulfur content approximately 400 mmol/kg dry weight, quantitatively consistent with other data on the zinc-insulin storage complex. Interestingly, a few granules with composition characteristic of beta granules were found in non-beta cells.