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 通过集合管进行酸碱运输并追踪酸碱的成熟 这种运输过程可以追溯到围产期。 拟议的 研究将集中在两种类型的酸碱转运细胞 在集合管中鉴定出 H+- 和 HCO3 离子分泌 插层（富含线粒体）细胞。 识别性和功能性 离体灌注兔集合管中单个细胞的测定 将使用最近开发的荧光染色技术进行， 包括那些探测线粒体、碳酸的存在的 脱水酶活性、胞吞作用/胞吐作用和凝集素的表面结合 并允许测量细胞 pH 值。 将测量净 HCO3 离子传输 通过微量热法。 为了识别功能极性 与 H+-ATPase 位置相关的两种类型的闰细胞 和Cl-HCO3离子交换剂，管腔阴离子取代Cl-的效果 将研究 HCO3 离子转运和细胞内 pH 值的影响。 因为 髓质集合管高 H+ 分泌率特征 （MCT）可能是由于相对酸性的髓质调节所致 环境中 HCO3 离子传输的调节响应 将检查与慢性系统性碱中毒的相关性 存在分泌H+-和HCO3离子的嵌入细胞的数量。 皮质集合中H+-和HCO3离子分泌细胞的频率 从遭受慢性干扰的动物中获得的肾小管（CCT） 代谢和呼吸酸碱状态和循环 盐皮质激素水平将与 HCO3 离子测量值进行比较 运输以证实可以诱导嵌入细胞的假设 扭转它们的功能极性。 功能性开发 分化的闰细胞的特征（碳 脱水酶、细胞 pH、胞吞作用/胞吐作用、表面糖蛋白）将 追溯到围产期和胚胎期，以建立 闰细胞的命运图。 作为调查的一部分 确定细胞何时以及如何开始分泌酸或 基础，嵌入和之间存在或不存在通信 主细胞将在未成熟的CCT中建立。 研究 这个应用程序中描述的应该让我们更好地理解如何 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 闰细胞。