ACTIVE POTASSIUM TRANSPORT ACROSS COLONIC EPITHELIUM

跨结肠上皮的活性钾转运

• 批准号: 3462930
• 负责人: DAN R HALM
• 金额: $ 8.65万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-08-01 至 1992-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3462930
• 关键词: biological fluid transport; chloride channels; colon; gastrointestinal absorption /transport; gastrointestinal epithelium; guinea pigs; ion transport; laboratory rabbit; microelectrodes; potassium channel; secretion; tissue /cell culture

The central goal of this projet is the characterization of the epithelial location and transport mechanisms responsible for active K secretion and absorption across the mammalian colon as well as the mechanisms that regulate these processes. Mammalian colon absorbs and secretes fluid by processes dependent on Na absorption and Cl secretion, respectively. Active K secretion and absorption occur and could be associated with either Na absorbing cells or Cl secreting cells. The location of the K transport processes will be determined using conventional and ion-selective microelectrodes, electron microprobe analysis of tissue composition, and fluorescence mocroscopy of living tissue. Electrophysiologic techniques will be employed to detect changes in cell membrane electrical potential and intracellular ion activity consistent with K secretion and absorption. Electron microprobe analysis of intracellular Na, K and Cl concentration will confirm the morphologic location of active K secretion an dabsorption. The possibility that K absorption is coupled to acid secretion will be examined using fluorescent probes of pH in conjunction with direct visualization using differential interference contrast microscopy. Regulation of K transport will be examined using the patch clamp technique and morphologic techniques. Activation of K and Cl channels by stimulators of transport will be examined with single channel recording from isolated colonic epithelia and primary cultures of these cells. Stimulation of Cl secretion alters the morphology of the vacuolated, columnar cell type in the colonic epithelium. Direct visualization of the morphologic changes involved in stimulation of secretion will be accomplished with differential interference contrast microscopy. These studies will provide a complete characterization of the location of active K transport in the colonic epithelium and permit an understanding of the ion transport events associated with intestinal fluid absorption and secretion.

该项目的中心目标是表征 上皮定位和运输机制负责 活性钾分泌和吸收通过哺乳动物结肠， 以及调节这些过程的机制。 哺乳动物结肠通过过程吸收和分泌液体 分别依赖于Na吸收和Cl分泌。 钾的分泌和吸收活跃， 有钠吸收细胞或氯分泌细胞。 位置 的K运输过程将确定使用 常规和离子选择性微电极、电子 组织成分和荧光的微探针分析 活组织的显微镜检查。 电生理技术将是 用于检测细胞膜电位的变化 和细胞内离子活性与K分泌一致， 吸收。 细胞内钠、钾离子的电子探针分析 和Cl浓度将确定 钾的分泌和吸收活跃。 可能K 吸收与酸分泌耦合，将使用 pH荧光探针结合直接可视化 使用微分干涉对比显微镜。 调控 用膜片钳技术检测钾离子转运 和形态学技术。 钾离子和氯离子通道的激活 将用单通道检查运输刺激物 从分离的结肠上皮细胞和原代培养物中记录 这些细胞。 Cl分泌的刺激改变了 结肠上皮中的空泡柱状细胞类型。 直接可视化的形态学变化涉及 刺激分泌将通过不同的 干涉衬度显微镜。 这些研究将提供一个 中活性钾运输位置的完整表征 结肠上皮，并允许了解离子 与肠液吸收相关的转运事件， 分泌物