RENAL INTERCALATED CELL REGULATION AND DIFFERENTIATION

肾间质细胞的调节和分化

• 批准号: 3462651
• 负责人: Lisa M. Satlin
• 金额: $ 11.82万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 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 1991-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3462651
• 关键词: acidity /alkalinity; calorimetry; cell differentiation; enzyme mechanism; exocytosis; fluorescence microscopy; fluorescent dye /probe; ion transport; kidney cell; kidney function; laboratory rabbit; membrane activity; phagocytosis; phosphatidylcholines; pinocytosis; radiotracer; receptor mediated endocytosis

The major objectives of this research project are to investigate the cellular and subcellular mechanisms responsible for the renal regulation of acid-base transport by the collecting duct and to trace the maturation of such transport processes back to the perinatal period. The proposed studies will focus on the two types of acid-base transporting cells identified in the collecting duct, the H+- and HCO3 ion-secreting intercalated (mitochondria-rich) cells. Identification and functional assay of individual cells in the isolated perfused rabbit collecting duct will be performed with recently developed fluorescence staining techniques, including those which probe for the presence of mitochondria, carbonic anhydrase activity, endocytosis/exocytosis and surface binding of lectins and permit measurement of cell pH. Net HCO3 ion transport will be measured by microcalorimetry. In order to identify the functional polarity of the two types of intercalated cells with respect to location of the H+-ATPase and Cl-HCO3 ion exchanger, the effect of luminal anion substitution for Cl- on HCO3 ion transport and intracellular pH will be studied. Because the high rate of H+ secretion characteristic of the medullary collecting tubule (MCT) may be due to conditioning by a relatively acidic medullary environment, regulation of HCO3 ion transport in this segment in response to chronic systemic alkalosis will be examined and the findings correlated with the numbers of H+- and HCO3 ion secreting intercalated cells present. The frequencies of H+- and HCO3 ion-secreting cells in cortical collecting tubules (CCT) obtained from animals subjected to chronic disturbances in metabolic and respiratory acid-base status and circulating mineralocorticoid levels will be compared with measurements of HCO3 ion transport to confirm the hypothesis that intercalated cells can be induced to reverse their functional polarity. The development of functional characteristics of the differentiated intercalated cell (carbonic anhydrase, cell pH, endocytosis/exocytosis, surface glycoproteins) will be traced back to the perinatal and embryonic periods in order to establish a fate map for the intercalated cell. As part of the investigation to determine when and how the cell becomes committed to secreting acid or base, the presence or absence of communication between intercalated and principal cells will be established in the immature CCT. The studies described in this application should allow us to better understand how metabolic and respiratory acid-base perturbations, mineralocorticoid excess, and genetic factors influence regulation and development of the intercalated cell.

该研究项目的主要目标是调查 负责肾脏调节的细胞和亚细胞机制 通过收集管道传输酸碱，并追踪成熟的成熟 这样的运输过程回到了围产期。 提议 研究将集中于两种类型的酸碱转运细胞 在收集管道中鉴定出H+ - 和HCO3离子分泌 插入（富含线粒体）的细胞。 识别和功能 在孤立的灌注兔收集管道中对单个细胞的测定 将使用最近开发的荧光染色技术进行 包括探测线粒体存在的碳 赤铁酶活性，内吞/胞吐作用和凝集素的表面结合 并允许测量细胞pH。 将测量净HCO3离子运输 通过微钙化法。 为了确定功能极性 相对于H+-ATPase位置的两种类型的插入细胞 和Cl-HCO3离子交换器，腔阴离子替代对Cl-的影响 将研究HCO3离子传输和细胞内pH。 因为 H+分泌特征的高速率的髓质收集小管 （MCT）可能是由于相对酸性的髓质调节 环境，该细分市场中HCO3离子运输的调节 将检查慢性全身性碱中毒，发现结果相关 H+ - 和HCO3离子的数量分泌的插入式细胞。 皮质收集中H+ - 和HCO3离子分泌细胞的频率 从遭受慢性干扰的动物获得的小管（CCT） 代谢和呼吸酸碱状态以及循环 矿物皮质激素水平将与HCO3离子的测量值进行比较 运输以确认可以诱导插入细胞的假设 扭转其功能极性。 功能的发展 分化的插入细胞的特征（碳 赤道酶，细胞pH，内吞和胞吞作用，表面糖蛋白）将是 追溯到围产期和胚胎时期，以建立一个 互联细胞的命运图。 作为调查的一部分 确定细胞何时以及如何致力于分泌酸或 基础，插入和 主要细胞将在未成熟的CCT中建立。 研究 本应用程序中描述的应该使我们能够更好地了解 代谢和呼吸酸碱扰动，盐皮质激素 过量和遗传因素影响调节和发展 插入细胞。