NA/ION REABSORPTION & H/ION SECRETION RENAL MECHANISMS

本提案的长期目标是表征离子 顶膜和基底膜亚群中的转运系统， 肾细胞的囊内细胞器。 另一个长期目标 是确定在细胞膜上调节离子转运的因子 水平 离子间存在动态关系的假设 细胞膜和胞内囊泡群中的转运蛋白 将被审查。 该项目的具体目标是：1。 以识别 并表征Na+、H+、K+、C1-等的转运系统 肾细胞膜中的阴离子。 2. 为了评价体内的作用， 调节（饮食、酸中毒、激素等）对肾细胞活性的影响 膜转运系统 3. 为了研究离子传输系统 在肾源性的连续细胞系中。 4. 为了确定所扮演的角色， 通过细胞内转运池调节肾细胞 膜转运系统（“膜再循环假说”）。 5. 到 评估二级站点的性质和监管作用（“修饰语 位点”），其可以通过以下方式调节转运活性： 动力学机制 将通过差速离心制备细胞膜群体， 密度梯度分离技术和逆流分布 在水两相系统中。 将通过以下方式识别膜群体： 标记酶测定和用电子显微镜进行形态学研究 显微镜 离子传输研究将使用标准同位素 用于测量跨膜pH的技术和荧光方法， 电压梯度 了解离子转运的机制和调节离子转运的因素 这些系统将是促进全面 了解肾功能，以及定义适应性 生理紊乱的变化。

The long term objective of this proposal is to characterize the ion transport systems in subpopulations of apical and basolateral membranes and of intravesicular organelles of renal cells. Another long term objective is to define the factors which regulate ion transport at the cell membrane level. The hypothesis that there is a dynamic relationship between ion transporters in the cell membrane and in intracellular vesicle populations will be examined. The specific aims of the project are: 1. To identify and characterize the transport systems for Na+, H+, K+, C1-, and other anions in renal cell membranes. 2. To evaluate the effects of in vivo conditioning (diet, acidosis, hormones, etc.) on the activity of renal cell membrane transport systems. 3. To investigate the ion transport systems in continuous cell lines of renal origin. 4. To determine the role played by intracellular pools of transpoerrts in the regulation of renal cell membrane transport systems ("membrane recycling hypothesis"). 5. To evaluate the nature and regulatory role of secondary sites ("modifier sites") on ion transport systems which may regulate transport activity by kinetic mechanisms. Cell membrane populations will be prepared by differential centrifugation, density gradient fractionation techniques, and counter-current distribution in aqueous 2-phase systems. Membrane populations will be identified by marker enzyme determinations and morphologic studies with an electron microscope. Ion transport studies will be done with standard isotopic techniques and fluorescence methods for measuring transmembrane pH and voltage gradients. Understanding the mechanisms of ion transport and factors which regulate these systems will be an important step in furthering the overall understanding of renal function, as well as defining the nature of adaptive changes to physiologic pertubations.