NMR STUDIES OF CATION TRANSPORT ACROSS BIOMEMBRANES

在这一建议中，我们力求继续证明 移位试剂技术应用的重要性 我们已经将其发展到23Na和39K NMR光谱， 组织。 SR的使用允许区分 生物金属阳离子的跨膜NMR信号。 而这 反过来，提供了阳离子的潜在定量 浓度和跨膜的连续监测 运输 我们建议合成和测试新的SR，寻求 提高效率，比较特异性等，我们还 建议测试新的弛豫试剂（RR）。 我们打算 仔细测量阳离子的核磁共振可见度 来自不同组织不同部分的信号。 我们希望 继续探索运输过程的本质， 可以通过这种方法观察它们的生物学和医学特性， 后果 因此，我们计划扩大我们的研究被动和 人红细胞和酵母中的主动Na+和K+转运。 对于后者，我们想测试我们认为是新发现的 离子转运与磷代谢的关系。 我们打算继续研究灌注的，跳动的大鼠 心 我们可以监测心肌细胞的Na+负荷 经过几次不同的干预。 组合SR和 RR实验将使我们能够研究 这些干预措施对间质性 和血管间隙。 我们还提出了新的SR实验上的 在活体大鼠脑中。 这些承诺的可能性，测定 血脑屏障（BBB）的相对通透性 不同大脑的体积和离子浓度 车厢，并监测运输的Li+跨越 BBB. 我们的实验主要采用标准的离体和体内 高分辨率NMR的体内方法学，在高场（更大 大于或等于7 T），存在于 自然丰富。 这项工作涉及到物理学的各个方面， 物理和无机化学，生物化学，生物物理学， 生理学，并在一些研究中产生了影响， 病理状况，包括心脏病和情感障碍 紊乱

In this proposal, we seek to continue to demonstrate the importance of the application of the shift reagent (SR) technique which we have developed to the 23Na and 39K NMR spectroscopy of tissue. The use of SR allows the discrimination of the transmembrane NMR signals of biological metal cations. This, in turn, provides for the potential quantitation of cation concentration and the continual monitoring of transmembrane transport. We propose to synthesize and test new SR, seeking increased effectiveness, compartimental specificity, etc. We also propose to test new relaxation reagents (RR). We intend to carry out careful measurements of the NMR-visibility of the cation signals from different compartments in different tissues. We wish to continue to explore the nature of the transport processes we can observe by this approach and their biological and medial consequences. Thus, we plan to extend our studies of passive and active Na+ and K+ transport in human erythrocytes and yeasts. With the latter, we want to test what we think is a newly found relationship between ion transport and phosphorus metabolism. We intend to continue our studies of the perfused, beating rat heart. We can monitor the Na+ -loading of the heart myocytes after a number of different interventions. Combination SR and RR experiments will allow us to investigate the apparent additional consequences of these interventions on the interstitial and vascular spaces. We also propose new SR experiments on the in vivo rat brain. These promise the possibilities of assaying the permeability of the blood-brain barrier (BBB), the relative volumes and ion concentrations of the different brain compartments, and the monitoring of transport of Li+ across the BBB. Our experiments mostly employ the standard ex vivo and in vivo methodology of high-resolution NMR, at high fields (greater than or equal to 7 T), of stable magnetic isotopes present in natural abundance. This work involves aspects of physics, physical and inorganic chemistry, biochemistry, biophysics, and physiology, and has ramifications in the study of a number of pathological conditions including heart disease and affective disorders.