PLASM MEMBRANE IN STIMULUS-SECRETION COUPLING

这项研究建议的长期目标是 确定葡萄糖质膜的作用- 刺激-分泌耦合中的反应性胰岛素瘤分析 它控制钙流的机制。 具体地说，我们希望实现以下目标：1) 电压依赖性钙通道的特性及其研究 对细胞内钙离子浓度和钙离子浓度的影响 胰岛素释放；2)研究β细胞对葡萄糖的转运 质膜；3)研究葡萄糖等对细胞膜的影响 胰岛素促分泌剂对Ca~(2+)-ATPase活性的影响 跨膜钙离子通量；4)观察补肾活血方对大鼠肾小球滤过率的影响。 胰岛素依赖型糖尿病患者的细胞膜抗体 钙通道，细胞内钙离子浓度， 胰岛素释放、葡萄糖转运和Ca2+-ATPase活性。至 完成这些目标，完整的β细胞或质膜 将使用准备工作。在完整的β细胞中，胰岛素释放和 细胞溶质钙浓度的变化 将在有无的情况下研究分泌剂 钙通道激动剂Bay K 8644及其拮抗剂 尼群地平在灌流系统中。同时胰岛素 将研究细胞内钙的释放和变化 在相同条件下的细胞悬浮液。此外，急性 促分泌剂对~3H-受体结合的慢性影响 尼群地平将在完整的胰岛素瘤细胞中进行研究。钙 通道也将在质膜中被表征 准备工作。 质膜制剂或膜泡将 也可以用来研究葡萄糖和其他己糖对 “钙泵，钙-镁-三磷酸腺苷酶。 由于质膜一直是抗体的靶子 在胰岛素依赖型糖尿病患者中发现，我们将使用 完整的细胞或由其制备的质膜 研究一种免疫球蛋白组分对肿瘤的影响 糖尿病患者参与了所有拟议的实验。这些研究将给出 关于质膜作为一种生物物质的功能的重要见解 胰岛素释放调节剂及其参与的 糖尿病的发病机制。

The long-range objective of this research proposal is to determine the role of the plasma membrane of a glucose- responsive insulinoma in stimulus-secretion coupling by analyzing the mechanisms by which it controls calcium fluxes. Specifically, we wish to accomplish the following: 1) to characterize voltage-dependent calcium channels and study their influence on the intracellular calcium ion concentration and insulin release; 2) to study glucose transport by the beta-cell plasma membrane; 3) to study the effect of glucose and other insulin secretagogues on Ca2+-ATPase activity and transmembrane calcium fluxes; 4) to investigate the effect of plasma membrane antibodies from insulin-dependent diabetics on calcium channels, interacellular calcium ion concentration, insulin release, glucose transport and Ca2+-ATPase activity. To accomplish these goals, intact beta-cells or a plasma membrane preparation will be used. In intact beta-cells, insulin release and changes in cytosol calcium concentrations in response to secretagogues will be studied in the presence and absence of the calcium channel agonist Bay K 8644 and the antagonist nitrendipine in a perifusion system. Simultaneously insulin release and changes in intracellular calcium will be studied in cell suspensions under identical conditions. In addition, acute and chronic effects of secretagogues on the binding of (3H)- nitrendipine will be studied in intact insulinoma cells. Calcium channels will also be characterized in a plasma membrane preparation. The plasma membrane preparation or membrane vesicles will also be used to study the effects of glucose and other hexoses on the "calcium-pump, Ca2+-Mg2+-ATPase. Since the plasma membrane has been the target of antibodies found in patients with insulin dependent diabetes, we will use intact cells or the plasma membranes preparation from this tumor to study the effect of an immunoglobulin fraction from diabetics on all proposed experiments. These studies will give important insight on the function of the plasma membrane as a regulator of insulin release and on its involvement in the pathogenesis of diabetes.