RENAL TRANSPORT AND HYDROLYSIS OF PEPTIDE HORMONES

肽激素的肾脏运输和水解

基本信息

批准号：
3153038
负责人：
Darryl Peterson
金额：
$ 10.23万
依托单位：
ROSALIND FRANKLIN UNIV OF MEDICINE & SCI
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-11-01 至 1987-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3153038
关键词：
gel electrophoresis glucagon hydrolysis insulin kidney metabolism peptide hormone peptide hormone metabolism radioimmunoassay radiotracer renal tubular transport thin layer chromatography tissue /cell culture

项目摘要

The kidneys play a major role in degrading peptide hormones. Since circulating peptides influence a host of vital functions, it is imperative to define more completely the hydrolytic processes. An understanding of these machanisms would provide: 1. a basis for synthesizing analogs resistant to hydrolysis; 2. an explanation for pathological conditions which may accompany alteration of the renal handling of toxic peptides; 3. a clearer picture of the kidney's role in conserving amino acids, and its influence upon the circulating levels of peptides. Recent work in our laboratory has indicated that certain small, linear peptides are hydrolyzed by enzymes in the renal brush border of the proximal tubule, followed by reabsorption of metabolites. The present proposal is intended to investigate the effects of altering size, composition, and structure of peptide molecules on the pattern of transport and hydrolysis. Specifically, labeled luteinizing hormone releasing hormone (LHRH), glucagon and insulin will be microperfused in separate experiments through rabbit renal tubular segments in vitro. Reabsorption of labeled material will be quantified, and products of hydrolysis or intact hormone appearing in the bathing medium and collection fluid will be studied by high voltage paper electrophoresis or descending paper chromatography. Analogs of LHRH will be similarly microperfused to examine the alterations of renal handling brought about by structural and compositional changes in the molecule. To more clearly define the degradative process, and identify the brush border as a site for enzymatic hydrolysis, the labeled peptide hormones will be incubated directly in the presence of microvilli membranes from rabbit brush border. Cleavage products will be characterized electrophoretically or chromatographically under varying conditions of temperature, time of incubation, and pH of the reaction mixture.

肾脏在降解肽激素中起着重要作用。自从循环肽会影响许多重要功能，这是必须的更完整地定义水解过程。对这些马奇主义将提供：1。合成类似物的基础对水解的抗性； 2。病理状况的解释可能会改变有毒肽的肾脏处理； 3。更清楚地了解了肾脏在保存氨基酸中的作用，其作用对肽循环水平的影响。我们实验室的最新工作表明某些小型线性肽在肾刷边界中的酶水解近端小管，然后再吸收代谢物。现在提案旨在研究变化大小的影响，肽分子的组成和结构在运输模式下和水解。具体而言，标记为黄体生成激素释放激素（LHRH），胰高血糖素和胰岛素将在单独的在体外通过兔肾小管段实验。重吸收标记的材料将被量化，以及水解产物或沐浴培养基中出现的完整激素和收集液将是由高压纸电泳或降纸研究色谱法。 LHRH的类似物将被同样用于检查结构性和分子的组成变化。更清楚地定义降解过程，并确定刷子边界作为酶水解的部位，标记为肽激素将直接在有微绒毛膜的情况下孵育兔子刷边界。切割产品将被描述在各种条件下进行电泳或色谱温度，孵育时间和反应混合物的pH。