NMR STUDIES OF METAL IONS IN INTACT CELLS AND TISSUES

细胞内金属离子调节多种细胞和组织 功能。我们研究的一个长期目标是了解可能的 这些离子在细胞增殖、分化、 音量调节，以及各种细胞过程的激素控制。我们 也试图了解细胞内离子的浓度是如何 由各种膜运输过程管理，以及这种调节是如何进行的 在癌症、高血压、糖尿病和镰刀等疾病中误入歧途 细胞疾病。我们的主要研究工具是核磁共振波谱。我们有 最近开发的测量游离Mg++的新的核磁共振方法(通过分析 细胞内ATP的31P核磁共振)和Na+离子(使用阴离子顺磁 我们引入试剂Dy(PPPI)2来区分内源和外源 胞外Na+离子)。我们研究的细胞和组织的选择 包括人类正常红细胞和镰刀状红细胞、外周血 淋巴细胞、分离的大鼠心肌细胞、两栖虫卵和鼠尾 动脉。要追求的具体目标是：(1)确定结合的Na+ 存在，并具有重要的功能，通过定量的核磁共振-可见和 不同类型细胞和细胞内总Na+离子浓度 生理状态；(2)如果确实有相当大一部分细胞内Na+在 我们的初步研究表明，人的红细胞是核磁共振--看不见的 实验，以确定它是否隔离在细胞膜和 细胞骨架，以及细胞内钙离子是否能释放； (3)研究Na+离子在细胞内各隔室的定位 在两栖类卵母细胞中；(5)找出是否部分松弛了~(23)Na-FT-核磁共振 光谱可以用来检测不同的隔间的存在 完整细胞内的松弛行为和磁环境；(5) 观察有丝分裂过程中[NaI]、Phi、[Mgi2+]的变化 同步分裂的两栖类卵母细胞的周期；(6)确定一个 细胞内Na+离子调节异常与 白血病细胞有丝分裂率和成熟顺序的研究 淋巴细胞；(7)测定正常和非淋巴细胞Na+、K+离子的状态。 处于充氧和脱氧状态的镰刀状红细胞； 探讨胰岛素对细胞膜系统的影响。 两栖类卵母细胞和哺乳动物心脏中Na~+、K~+和H~+离子的转运 并确定这种效应是否由 蛋白质分解产生的多肽；以及(9)检验假设 核磁共振可见的细胞内Na+增加与必要的 高血压。

Intracellular metal ions modulate a variety of cellular and tissue functions. A long range goal of our research is to understand possible regulatory roles of these ions in cellular proliferation, differentiation, volume regulation, and hormonal control of various cellular processes. We seek also to understand how the concentrations of intracellular ions are managed by various membrane transport processes, and how such regulation goes astray in disorders such as cancer, hypertension, diabetes, and sickle cell disease. Our primary research tool is NMR spectroscopy. We have recently developed new NMR approaches for measuring free Mg++ (by analyzing 31P NMR of intracellular ATP) and Na+ ions (using an anionic paramagnetic reagent Dy(PPPi)2 introduced by us to distinguish between intra- and extracellular Na+ ions). The choice of cells and tissues for our research includes human normal and sickle erythrocytes, peripheral blood lymphocytes, isolated rat cardiac myocytes, amphibian eggs, and rat tail artery. Specific aims to be pursued are: (1) To determine if bound Na+ exists, and is functionally significant, by quantitating NMR-visible and total intracellular Na+ ion concentrations in various types of cells and physiological states; (2) If indeed a sizable part of intracellular Na+ in human erythrocytes is NMR-invisible as indicated by our preliminary experiments, to determine if it is sequestered in the cell membrane and cytoskeleton, and whether it can be released by intracellular Ca++ ions; (3) To study localization of Na+ ions in various intracellular compartments in amphibian oocytes; (5) To find out if partially relaxed 23Na FT NMR spectra can be used to detect the existence of compartments with differing relaxation behaviour and magnetic environments within an intact cell; (5) To follow changes in [Nai], pHi, [Mgi2+] during mitotic cell division cycles in synchronously dividing amphibian oocytes; (6) To ascertain if an abnormality in the regulation of intracellular Na+ ions is associated with the disordered mitotic rate and maturation sequence of leukemic lymphocytes; (7) To characterize the state of Na+ and K+ ions in normal and sickle red blood cells in oxygenated and deoxygenated states; (8) To investigate the effects of insulin upon membrane systems involved in the transport of Na+, K+ and H+ ions in amphibian oocytes and mammalian cardiac myocytes and to determine whether such effects are mediated by proteolytically generated peptides; and (9) To test the hypothesis that an increased NMR-visible intracellular Na+ is associated with essential hypertension.