PLASM MEMBRANE IN STIMULUS-SECRETION COUPLING

刺激分泌耦合中的质膜

• 批准号: 3447626
• 负责人: MARGARETHE E HOENIG
• 金额: $ 5.25万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-01-01 至 1989-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3447626
• 关键词: adenosinetriphosphatase; aminoacid transport; antibody; calcium channel blockers; cell membrane; fluorescence spectrometry; glucose transport; hormone regulation /control mechanism; immunoglobulins; insulin; pancreatic islet neoplasm; pancreatic islets; radioimmunoassay; secretion

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.

本研究计划的长期目标是 确定葡萄糖质膜的作用 通过分析刺激-分泌耦合中的反应性胰岛素瘤 它控制钙通量的机制。 具体来说，我们希望实现以下目标：1） 表征电压依赖性钙通道并研究其 对细胞内钙离子浓度的影响 胰岛素释放； 2) 研究β细胞的葡萄糖转运 质膜； 3）研究葡萄糖等的影响 胰岛素促分泌剂对 Ca2+-ATPase 活性的影响 跨膜钙通量； 4) 考察效果 胰岛素依赖型糖尿病患者的质膜抗体 钙通道、细胞间钙离子浓度、 胰岛素释放、葡萄糖转运和 Ca2+-ATP 酶活性。 到 完成这些目标，完整的β细胞或质膜 将使用准备。 在完整的β细胞中，胰岛素释放和 细胞质钙浓度的变化响应 将在存在和不存在的情况下研究促分泌剂 钙通道激动剂 Bay K 8644 及其拮抗剂 尼群地平在灌注系统中的应用。 同时注射胰岛素 将研究细胞内钙的释放和变化 相同条件下的细胞悬液。 此外，急性 以及促分泌剂对 (3H)- 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 通道也将在质膜中进行表征 准备。 质膜制剂或膜囊泡将 也可用于研究葡萄糖和其他己糖对 “钙泵，Ca2+-Mg2+-ATP酶。 由于质膜一直是抗体的目标 在胰岛素依赖型糖尿病患者中发现，我们将使用 完整的细胞或由此制备的质膜 肿瘤研究免疫球蛋白组分的作用 糖尿病患者参与所有提议的实验。 这些研究将给出 关于质膜作为细胞膜的功能的重要见解 胰岛素释放的调节因子及其参与 糖尿病的发病机制。