US-Poland Research on Hormonal Control of Calcium Transport Across the Plasma Membrane in Hepatocytes

美国-波兰关于肝细胞中钙跨质膜运输的激素控制的研究

• 批准号: 9118311
• 负责人: Kathryn Lanoue
• 金额: $ 2.85万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-08-15 至 1997-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9118311&HistoricalAwards=false
• 关键词: US; Poland; Research; Hormonal; Control

This U.S.-Poland research project between Dr. Kathryn F. Lanoue of Pennsylvania State University Hershey Medical Center and Jerzy Duszinski of the Nencki Institute of Warsaw, Poland, is to identify and characterize the transporter which catalyzes hormone dependent influx of extracellular calcium into liver cells. The researchers will study fura-2 loaded hepatocytes in primary culture, using a fluorescence digital imaging system in conjunction with whole cell patch clamp microinjection techniques, to determine the current voltage relationships of the putative calcium channel, as well as the enthalpy of calcium influx and its Ph dependence. Preliminary experiments indicate the calcium transport into the cell is not dependent on hormone occupancy of calcium mobilizing receptors in the plasma membrane, or on IP3 levels in the cell but it is dependent on the extent of depletion of intracellular hormone releasable calcium stores. Calcium depletion of these stores stimulates calcium entry into the cell, in a graded manner. The researchers will test the hypothesis that a calcium sensitive enzyme in the endoplasmic reticulum elaborates and releases to the cytosol a metabolite which regulates plasma membrane calcium permeability. They will design experiments to demonstrate the existence of such a diffusible metabolite and to characterize it. The researchers plan to use an inhibitor of the calcium plasma membrane transporter as a means to monitor calcium transporter activity in hepatocyte plasma membrane vesicles loaded with fura-2. They will use the vesicular assay system to screen the influence of putative regulators and as a basis for later solubilization, reconstitution, and purification. %%% This project in biology fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool resources in areas of strong mutual interest and competence.

宾夕法尼亚州立大学好时医学中心的Kathryn F.Lanoue博士和波兰华沙Nencki研究所的Jerzy Duszinski博士开展的这项美国-波兰研究项目旨在鉴定和表征催化激素依赖的细胞外钙流入肝细胞的转运体。研究人员将在原代培养中研究Fura-2负载的肝细胞，使用荧光数字成像系统结合全细胞膜片钳微注射技术，以确定可能的钙通道的电流电压关系，以及钙内流的焓及其对Ph的依赖。初步实验表明，钙向细胞内的转运不依赖于质膜上钙动员受体的激素占有率，也不依赖于细胞内IP3水平，而取决于细胞内可释放激素的钙库的耗尽程度。这些钙库的钙消耗刺激钙以一种分级的方式进入细胞。研究人员将测试这一假设，即内质网中的一种钙敏感酶负责制定并向胞浆释放一种调节质膜钙通透性的代谢物。他们将设计实验来证明这种可扩散代谢物的存在并对其进行表征。研究人员计划使用钙质膜转运蛋白的抑制剂作为监测携带Fura-2的肝细胞质膜囊泡中钙转运蛋白活性的一种手段。他们将使用囊泡分析系统来筛选可能的调节剂的影响，并作为以后增溶、重组和纯化的基础。这个生物学项目通过使美国和东欧的顶尖专家能够将互补的人才结合在一起，并在相互感兴趣和能力很强的领域汇集资源，从而实现了促进科学知识的计划目标。