ADAPTIVE REGULATION OF NUTRIENT TRANSPORT BY THE GUT

该项目位于营养学和胃肠病学之间的界面。 它询问肠道的营养更新机制是如何自适应地 通过饮食和其他条件的变化来调节。 长期目标集中在三个问题上。 1.有哪些 随着饮食变化、怀孕和 其他正常和疾病相关的情况？ 2.有哪些机制 对这些模式负责吗 (e.g.,具体变化 运输系统、粘膜质量或Na+梯度）。 3.有哪些 这些变化的信号？(e.g.,运输溶质，激素， 或胰胆分泌物）。 这项建议的具体目标有两个方面： 1.肠道氨基酸（AA）的更新如何随饮食而变化？ 蛋白质含量？ 特别是，如何每一个主要的摄取 AA的机制由蛋白质作为来源的不同作用调节 卡路里氮和必需AA的含量吗 2.成年个体的营养吸收是否受到 断奶后不久个体饮食，或其 母亲在怀孕和哺乳期间的饮食习惯？ 就是有没有 营养吸收规划中的任何关键期现象 机制？ 将使用的主要方法将测量示踪剂吸收;到一个小得多的 程度、电生理参数、形态测量和激素水平。 该项目对健康有重大影响：1。的影响 蛋白质营养不良（营养不良）对氨基酸摄取的影响， 营养不良; 2。改变血浆中维生素C水平的健康后果 由于肠道营养吸收的改变， 怀孕、衰老、饮食改变等正常情况; 3.改变 胃切除术后短肠吸收不良综合征的营养摄取 综合征、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.