近日，上海交通大学孔学谦团队实现了用核磁共振测量细胞内钠转运。2026年1月15日出版的《美国化学会志》发表了这项成果。

钠离子对维持电解质平衡、神经冲动传导及肌肉收缩等多项生理功能至关重要。跨细胞膜的钠离子转运失调与代谢综合征、神经系统疾病及心血管疾病等多种健康问题密切相关。然而，现有评估细胞内钠离子活性的方法常存在局限性：或具有侵入性，或难以捕捉动态变化。

研究组提出一种非侵入性的²³Na核磁共振方法，可直接量化活细胞中钠离子的跨膜转运速率。该技术将弛豫交换谱与多位点交换模型相结合，可在亚秒级时间尺度上研究钠离子转运动力学。其关键优势在于能利用内源性核磁共振弛豫差异区分细胞内/外钠离子池，从而避免使用可能干扰细胞状态的外源性试剂。在人类细胞系中开展的实验成功验证了该技术区分不同生理状态的能力，例如在离子通道被药物阻断或激活时的差异检测。通过该方法测得的钠离子转运速率与细胞内钠离子分数，均与细胞代谢活性呈现明确相关性，为体外监测跨膜离子动力学提供了有价值的量化指标。

附：英文原文

Title: Measuring Sodium Transport in Cells with Nuclear Magnetic Resonance

Author: Juntao Xia, Yu Yin, Yun Chen, Xuetao Wu, Haoyu Li, Yaqin Liu, Qingping He, Yun Ji, Ke Ma, Bona Dai, Hongzhen Bai, Fan Yang, Ruiliang Bai, Xueqian Kong

Issue&Volume: January 15, 2026

Abstract: Sodium ions (Na+) are fundamental to numerous physiological functions, such as maintaining electrolyte balance, enabling nerve impulse transmission, and facilitating muscle contraction. Dysregulation of Na+ transport across cell membranes is implicated in a range of health issues including metabolic syndromes, neurological conditions, and cardiovascular diseases. However, current methods for assessing cellular Na+ activity often face limitations; they can be invasive or fail to capture dynamic changes. In this study, we introduce a noninvasive 23Na nuclear magnetic resonance (NMR) methodology designed to directly quantify the transport rate of sodium ions in living cells. Our technique integrates relaxation exchange spectroscopy (REXSY) with a multisite exchange model, enabling the investigation of Na+ transport dynamics on a time scale of subseconds. A key advantage is its ability to differentiate between intracellular and extracellular Na+ pools based on the endogenous NMR relaxation difference, thereby avoiding the need for potentially disruptive exogenous reagents. Experiments conducted on human cell lines successfully demonstrated the technique’s capacity to distinguish between various physiological states, such as when ion channels are pharmacologically blocked or activated. The resulting measurements of Na+ transport rates and intracellular Na+ fractions show a clear correlation with cellular metabolic activity, offering valuable quantitative markers for monitoring transmembrane ion dynamics in vitro.

DOI: 10.1021/jacs.5c15916

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c15916