In recent years, there has been remarkable progress in the field of dissolution dynamic nuclear polarization (D-DNP). This method has shown significant potential for enhancing nuclear polarization by over 10,000 times, resulting in a substantial increase in sensitivity. The unprecedented signal enhancements achieved with D-DNP have opened new possibilities for in vitro analysis. This method enables the monitoring of structural and enzymatic kinetics with excellent time resolution at low concentrations. Furthermore, these advances can be straightforwardly translated to in vivo magnetic resonance imaging and magnetic resonance spectroscopy (MRI and MRS) experiments. D-DNP studies have used a range of 13C labeled molecules to gain deeper insights into the cellular metabolic pathways and disease hallmarks. Over the last 15 years, D-DNP has been used to analyze glutamine, a key player in the cellular metabolism, involved in many diseases including cancer. Glutamine is the most abundant amino acid in blood plasma and the major carrier of nitrogen, and it is converted to glutamate inside the cell, where the latter is the most abundant amino acid. It has been shown that increased glutamine consumption by cells is a hallmark of tumor cancer metabolism. In this review, we first highlight the significance of glutamine in metabolism, providing an in-depth description of its use at the cellular level as well as its specific roles in various organs. Next, we present a comprehensive overview of the principles of D-DNP. Finally, we review the state of the art in D-DNP glutamine analysis and its application in oncology, neurology, and perfusion marker studies.

中文翻译：

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谷氨酰胺：超极化磁共振揭示的人体新陈代谢的关键参与者


近年来，溶出动态核极化 （D-DNP） 领域取得了显著进展。该方法已显示出将核极化增强 10,000 倍以上的巨大潜力，从而显着提高灵敏度。D-DNP 实现了前所未有的信号增强，为体外分析开辟了新的可能性。该方法能够在低浓度下以出色的时间分辨率监测结构和酶动力学。此外，这些进展可以直接转化为体内磁共振成像和磁共振波谱（MRI 和 MRS）实验。D-DNP 研究使用一系列 13C 标记分子来更深入地了解细胞代谢途径和疾病标志。在过去的 15 年里，D-DNP 已被用于分析谷氨酰胺，谷氨酰胺是细胞代谢的关键参与者，与包括癌症在内的许多疾病有关。谷氨酰胺是血浆中含量最丰富的氨基酸，也是氮的主要载体，它在细胞内转化为谷氨酸，其中后者是最丰富的氨基酸。已经表明，细胞消耗增加谷氨酰胺是肿瘤癌代谢的标志。在这篇综述中，我们首先强调了谷氨酰胺在代谢中的重要性，深入描述了它在细胞水平上的使用以及它在各种器官中的具体作用。接下来，我们全面概述了 D-DNP 的原理。最后，我们回顾了 D-DNP 谷氨酰胺分析的最新进展及其在肿瘤学、神经学和灌注标志物研究中的应用。