NMR STUDIES OF CELLULAR METABOLISM

本项目是针对活体核磁共振的发展和应用而开发的 新陈代谢及其扰动的光谱研究方法 化学毒素。过去一年的两项主要申请是： (1)测量或测量兔玻璃体腔内的氧气水平 眼睛，以及各种因素对眼睛的干扰，以及(2)影响的研究 硼酸对支持细胞碳水化合物代谢的影响。在 第一系列研究，氧气水平是根据 自旋晶格驰豫速率随浓度变化的微扰 全氟三丁胺。此方法要求所有或一个 部分玻璃体体液被全氟化碳取代。二 进行了各种类型的测量，其中一种是玻璃体 完全被替换了，第二次是5微米的小球体 全氟化碳被放置在眼睛里。对血液的损害的影响- 对玻璃体氧气水平上的视网膜屏障进行了量化，并对 类固醇的保护作用得到证实。 第二系列研究的目的是了解生理学上的 硼酸和硼酸的影响以及有毒物质的潜在基础 已报道的这些化合物的作用。虽然硼是一种 植物的基本元素，在动物系统中不需要 已经成立了。最近已经证明，在相对较高的水平上 水平的硼酸对男性生殖系统有选择性的毒性。 硼酸对支持细胞代谢影响的核磁共振研究 已经使用碳-13标记的葡萄糖进行了培养。首字母A 一系列的测量表明，谷氨酰胺/谷氨酸的比率是 在暴露于硼酸的细胞中显著减少。

This program is aimed at the development and application of in vivo NMR spectroscopic methods for studying metabolism and its perturbation by chemical toxins. The two primary applications during the past year were: (1) measurements or oxygen levels in the vitreous compartment of the rabbit eye, and its perturbation by various agents, and (2) studies of the effects of boric acid on the carbohydrate metabolism of Sertoli cells. In the first series of studies, oxygen levels have been determined based on the concentration-dependent perturbation of the spin lattice relaxation rate of perfluorotributyl amine. This approach requires that either all or a portion of the vitreous humor be replaced by the perfluorocarbon. Two types of measurement were carried out, one in which the vitreous was entirely replaced, and a second in which small, 5 um spheres of perfluorocarbon were placed in the eye. Effects of damage to the blood- retinal barrier on the oxygen level of the vitreous were quantified, and a protective effect of steroids was demonstrated. A second series of studies is aimed at understanding the physiological effects of boric and boronic acids, and the potential basis for the toxic effects of these compounds which have been reported. Although boron is an essential element for plants, no need in animal systems has been established. Recently it has been demonstrated that at relatively high levels boric acid is selectively toxic to the male reproductive system. NMR studies of the effects of boric acid on the metabolism of sertoli cell cultures have been carried out using carbon-13 labeled glucose. An initial series of measurements indicates that the glutamine/glutamate ratio is significantly reduced in cells exposed to boric acid.