MG TURNOVER AND EXCHANGE--FUNCTIONAL SIGNIFICANCE

描述：(改编自申请人的摘要)基于初步 数据，舒伊特博士相信她现在有办法解决 大量细节，内源性镁调控的重要问题 周转、器官-器官镁交换的动态及量化 表观镁可交换池大小。因此，建议对此进行调查 镁代谢动态指标之间的函数关系 以及在三种截然不同的情况下细胞功能的直接测量 生理条件包括：1)镁摄入量水平的影响， 镁的缺乏以及在足够的范围内；2)影响 K缺乏或K+镁联合缺乏；3)慢性 运动或运动加镁缺乏。在每一个实验中，她都会 检查特定饮食和/或运动引起的变化的影响 随着时间的推移，镁代谢的同位素测量。这些方面的变化 然后，参数将与评估的细胞功能的变化相关 测定Na-K-ATPase活性和细胞超微结构。此外，她还 将尝试识别特定的细胞内镁池，这些池可能是 被改变软组织镁状态的条件耗尽。三位一体 她提出要探索的实验条件都改变了某些方面(S) 整个动物的镁代谢，但对细胞外的影响有很大不同 毫克水平。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况评价 浓度。

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.