ADAPTIVE REGULATION OF NUTRIENT TRANSPORT BY THE GUT

该项目位于营养学和胃肠病学之间的交界处。 它询问肠道的营养更新机制是如何适应的 受饮食和其他条件变化的调节。 长期目标集中在三个问题上。1.什么是 营养更新的变化模式随饮食变化、怀孕和 其他正常或与疾病相关的情况？2.发病机制是什么 对这些模式中的每一个负责？(例如，特定的更改 运输系统、粘膜质量或钠离子梯度)。3.什么是 这些变化的信号是什么？(例如，运输的溶质本身，激素， 或胰胆管分泌物)。 这项建议的具体目的有两个： 1.氨基酸(AA)的肠道更新如何随饮食变化 蛋白质含量？特别是，每一个主要的领悟是如何 蛋白质作为来源的不同作用对氨基酸的调节机制 卡路里、氮和必需的氨基酸？ 2.成年个体的营养摄取是否受到任何 不可逆的方式，通过断奶后不久的个人饮食，或通过其 母亲在孕期和哺乳期的饮食？就是，有没有 营养吸收规划中的任何临界期现象 机械装置？ 将使用的主要方法将测量示踪剂的摄取量； 范围、电生理参数、形态测量和激素水平。 该项目对以下方面有重大的健康影响：1 蛋白质营养不良(夸希奥克)对氨基酸摄取、反馈的影响 营养不良；2.血浆水平改变对健康的影响 由于肠道营养物质摄取改变而导致的营养物质 正常情况，如怀孕、衰老和改变饮食；3.改变 短肠胃切除术后吸收不良综合征患者的营养摄取 综合症、糖尿病和其他疾病状态。

This project lies at the interface between nutrition and gastroenterology. It asks how the nutrient update mechanisms of the intestine are adaptively regulated by changes in diet and other conditions. The long-term objectives focus on three questions. 1. What are the patterns of changes in nutrient update with diet changes, pregnancy, and other normal and disease related conditions? 2. What are the mechanisms responsible for each of these patterns? (e.g., change in specific transport system, mucosal mass, or the Na+ gradient). 3. What are the signals for these changes? (e.g., transported solutes themselves, hormones, or pancreaticobiliary secretions). The specific aims of this proposal are two-fold: 1. How does intestinal update of amino acids (AA's) vary with dietary protein content? In particular, how are each of the major uptake mechanisms for AA's regulated by the distinct roles of protein as a source of calories, nitrogen, and essential AA's? 2. Is nutrient uptake in the adult individual influenced in any irreversible way by that individual's diet shortly after weaning, or by its mother's diet during the gestation and nursing periods? That is, are there any critical-period phenomena in the programming of nutrient uptake mechanism? The main methods to be used will measure tracer uptake; to a much lesser extent, electrophysiological parameters, morphometry, and hormone levels. The project has major health-related implications for: 1. effects of protein malnutrition (kwashiorkor) on amino acid uptake, feeding back onto the malnutrition; 2. health consequences of altered plasma levels of nutrients due to altered intestinal nutrient uptake, resulting in turn from normal conditions such as pregnancy, aging, and changed diet; 3. altered nutrients uptake in post-gastrectomy malabsorption syndrome, short-bowel syndrome, diabetes, and other disease states.