MG TURNOVER AND EXCHANGE--FUNCTIONAL SIGNIFICANCE

描述：（改编自申请人摘要）基于初步 数据，Schuett博士认为，她现在有办法解决， 实质性的细节，内源性镁调控的重要问题 周转，器官-器官镁交换的动态和定量 表观Mg可交换库大小。 因此，建议调查 这些镁代谢动态指标之间的函数关系 直接测量细胞功能， 生理条件包括：1）镁摄入水平的影响， 镁缺乏以及在足够的范围内; 2）的影响， 缺钾或缺钾加缺镁; 3）慢性 运动或运动加镁缺乏。 在每一个实验中， 检查特定饮食和/或运动引起的变化的影响 镁代谢的同位素测量。 未来基本假设条件发生变化 然后，参数将与评估的细胞功能的变化相关 Na+-K+-ATP酶活性和细胞超微结构。 此外她 将试图确定特定的细胞内镁池， 由于改变软组织镁状态的条件而耗尽。 三 她提出的实验条件都改变了一些方面， 整个动物的镁代谢，但有非常不同的影响细胞外 镁水平。 因此，拟议的研究组合提供了独特的 有机会测试他们的同位素方法的有效性， 面对不同细胞外镁的软组织镁状态评估 浓度的

DESCRIPTION: (Adapted from applicant's abstract) Based on preliminary data, Dr. Schuett believes that she now has the means to address, in substantial detail, the important issues of regulation of endogeneous Mg turnover, the dynamics of organ-organ Mg exchange and quantification of apparent Mg exchangeable pool size. Thus, it is proposed to investigate the functional relationship between these dynamic measures of Mg metabolism and direct measures of cellular function under three very different physiologic conditions to include: 1) the effect of level of Mg intake, both Mg deficient as well as within the sufficient range; 2) the effect of K deficiency or combined K plus Mg deficiency; and 3) the effect of chronic exercise or exercise plus Mg deficiency. In each experiment she will examine the effect of the specific dietary and/or exercise-induced changes in isotopic measures of Mg metabolism over time. Changes in these parameters will then be related to changes in cellular function as assessed by Na+ K+ ATPase activity and cellular ultrastructure. In addition, she will attempt to identify particular intracellular pools of Mg that may be depleted by conditions that alter soft tissue Mg status. The three experimental conditions she proposed to explore all alter some aspect(s) of whole animal Mg metabolism but have very different effects on extracellular Mg levels. Thus, the proposed combination of studies offers the unique opportunity to test the validity of their isotopic approaches to the assessment of soft tissue Mg status in the face of varying extracellular Mg concentrations.