ION TRANSPORT & ITS REGULATION IN PROXIMAL RENAL TUBULES

离子传输

• 批准号: 3238166
• 负责人: ELSA N. BELLO-REUSS
• 金额: $ 3.74万
• 依托单位: UNIVERSITY OF TEXAS MED BR GALVESTON
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-08-01 至 1988-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3238166
• 关键词: acetylcholine; apical membrane; basolateral membrane; biological fluid transport; chlorine; dopamine; electrophysiology; epithelium; glomerular filtration; ion transport; membrane permeability; membrane potentials; microelectrodes; neurotransmitters; norepinephrine; potassium; renal tubular transport; renal tubule; sodium; acetylcholine; apical membrane; basolateral membrane; biological fluid transport; chlorine; dopamine; electrophysiology; epithelium; glomerular filtration; ion transport; membrane permeability; membrane potentials; microelectrodes; neurotransmitters; norepinephrine; potassium; renal tubular transport; renal tubule; sodium

The mechanism of ion transport and their modifications by several neurotransmitters will be studied with electrophysiological techniques in isolated perfused segments (S1, S2, S3) of rabbit proximal tubules. Experiments are designed 1) to determine the passive properties of apical and basolateral membranes and paracellular pathway by measuring a) transepithelial resistance, b) apparent ratio of apical to basolateral membrane resistance, and c) cell membrane potentials. These data will allow us to calculate the equivalent electrical resistances and electromotive forces of the cell membranes. Ionic substitutions will be used to determine the ionic diffusional permeability of the cell membranes. 2) To study the effects of norepinephrine, dopamine, acetylocholine and other substances which modify fluid reabsorption on the passive properties of the cell membranes. 3) To determine the steady-state intracellular activities of Na, K and C1, by using ion-sensitive microelectrodes to define uphill and downhill transport process and to ascertain whether passive ion transport at a given membrane can be electrodiffusional. If these experiments are successful, intracellular ion activity measurements will be applied to the study of the mechanism of action of neurotransmitters which modify fluid transport. These experiments should provide a better understanding of proximal tubular function and of the regulation of fluid transport by the kidney as a whole.

离子传输的机制及其修饰 神经递质将使用电生理技术研究 兔近端小管的分离灌注片段（S1，S2，S3）。 设计实验1）确定顶端的被动特性 通过测量A）以及基底外侧膜和细胞细胞途径 transepithial抗性，b）顶端与基底外侧的明显比率 膜电阻和C）细胞膜电位。 这些数据将 允许我们计算等效的电阻和 细胞膜的电动力。 离子替代将是 用于确定细胞的离子扩散渗透性 膜。 2）研究去甲肾上腺素，多巴胺的作用， 乙氯胆碱和其他修饰液体重吸收的物质 细胞膜的被动特性。 3）确定稳态 通过使用离子敏感的Na，K和C1的细胞内活性 微电极定义上坡和下坡运输过程，并 确定在给定膜上是否可以是被动离子传输 电源。 如果这些实验成功，则细胞内离子 活动测量将应用于研究 神经递质改变流体转运的作用。 这些 实验应更好地了解近端管状 整个肾脏的功能和调节流体转运的功能。