GASTRIC ACID SECRETION--CATION BINDING WITH H,K-ATPASE

胃酸分泌--阳离子与 H,K-ATP酶的结合

• 批准号: 3232620
• 负责人: EDWIN C RABON
• 金额: $ 1.48万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-08-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3232620
• 关键词: active sites; active transport; adenosinetriphosphatase; animal tissue; chemical binding; enzyme inhibitors; enzyme structure; fluorescent dye /probe; gastric acid; inhibitor /antagonist; membrane transport proteins; potassium channel; protein structure function; quinoline analog; radiotracer; rubidium; secretion

The long term goal of this study is to define the K+ transport mechanisms used to regulate the transcellular flow of K+ during gastric acid secretion. We have developed an assay of 86Rb- flux which discriminates ATPase and conductance mediated K+ transport to characterize secretory stimulusdependent K+ movement across the basolateral (BLM) and secretory (SM) membranes of vesicle preparations and intact and permeabilized isolated parietal cells of the New Zealand white rabbit. The K+ conductance will be characterized will respect to (i) specific stimulus dependence (ii) cationic selectivity (iii) inhibitor specificity (iii) regulation by specific second messenger mediators. The stimulus response of the Na, K-ATPase will be determined in the isolated cell preparation by the (3H) ouabain binding assay of Hootman and Williams and compared with that of the BLM K+ conductance (J. Physiol (1985) 360:121-134). The K+ conductance of the SM will be solubilized and functionally reconstituted to extend the characterization of this peptide with respect to (i) disenness of inhibitors and physiological moderators and (ii) to begin the initial purfication of the conductance peptide. The appearance of the K+ conductance and specific peptides labeled with the use dependent H,K-ATPase inhibitor (14C) omeprazole will be correlated in stimulated and resting SM preparations to distinguish between possible mechanisms of activation (i.e. appearance of the potassium conductance in parallel with the H,K-ATPase) by a membrane fusion process involving the insertion of a K+ conductance into the SM or covalent modification of an inactive conductance peptide always present in the membrane. These studies suggest that K+ conductances are targets for the physiological regulation of gastric acid secretion. The model system and assays developed here could provide important tools for the study of the pharmacology of the K+ conductance peptide as a means of control of gastric acid secretion.

本研究的长期目标是确定K+运输 用于调节K+跨细胞流动的机制 胃酸分泌 我们建立了一种~（86）Rb通量测定方法 区分ATP酶和电导介导的K+ 分泌刺激依赖性K+转运 基底外侧运动（BLM）和分泌运动（SM） 囊泡制剂的膜和完整的和透化的 新西兰白色兔的分离壁细胞。 第K+ 电导将被表征为将关于（i）特定的 刺激依赖性（ii）阳离子选择性（iii）抑制剂 特异性（iii）特定第二信使的调节 调解员 Na，K-ATP酶的刺激反应将是 通过（3 H）哇巴因在分离的细胞制备物中测定 Hootman和威廉姆斯的结合试验，并与 BLM K+电导（J. Physiol（1985）360：121-134）。 第K+ SM的电导将被溶解，并且在功能上 重构以扩展该肽的表征， 关于（i）抑制剂和生理调节剂的不一致性 和（ii）开始电导肽的初始纯化。 K+电导和特异性肽的出现 使用依赖性H，K-ATP酶抑制剂（14 C）标记 奥美拉唑将在刺激和静息SM中相关 准备区分可能的机制， 激活（即， 与H，K-ATP酶平行）通过膜融合过程 涉及在SM中插入K+电导，或者 非活性导电肽的共价修饰总是 存在于膜中。 这些研究表明，K+ 电导是生理调节的目标， 胃酸分泌 开发的模型系统和测定法 这里可以提供重要的工具，研究 K+传导肽的药理学作为一种手段， 控制胃酸分泌。