Millart H, Durlach V, Durlach J
Laboratoire de Pharmacologie-Toxicologie, Hôpital Maison Blanche, Reims, France.
Magnes Res. 1995 Mar;8(1):65-76.
In order to assess total magnesium concentrations in human red blood cells (erythrocytes--ErMg), atomic absorption spectrometry (AAS) provides high accuracy and precise method rapid and amenable to automation. Taking care of eliminating the chronic marginal magnesium deficits, normal values of ErMg evaluated through a direct method and expressed as mmol/litre of packed cells are 2.3 +/- 0.24. Inductively coupled plasma-mass spectromettry (ICP-MS) is a multielemental analytical technique. Particle induced x-ray emission (PIXE) also provides multielemental capability, but is time-consuming and costly. Microelectrodes are the gold standard for intracellular Mg2+ measurements. But microelectrodes and fluorescence probes measure the activity of magnesium ions, not the concentrations. Ionized magnesium content of human intact erythrocyte is mainly assessed with the NMR method and with the zero point titration. The concentration of ionized magnesium as estimated by NMR (31P NMR method) was found to be 0.20 +/- 0.02 mmol/litre cell water and with the zero point titration 0.55 +/- 0.12. The uncertainty concerning the two current used techniques for free magnesium determination is worsened by the fact that magnesium inside red cells continually oscillates in vivo. Free magnesium constitutes a small part of total magnesium. Further studies are necessary to assess the importance of its variations in clinical medicine. Efflux of ErMg is controlled through membranous sodium-dependent and sodium-independent pathways and through genetic and neurohormonal regulations. Variations in the total or ionized ErMg do not necessarily mean that similar changes should exist in the magnesium pool. But it remains the basic static cellular magnesium item. Its value will be subsequently enhanced when it takes place among the clinical and paraclinical data of dynamic magnesium investigations.
为了评估人体红细胞中的总镁浓度（红细胞镁——ErMg），原子吸收光谱法（AAS）提供了一种高精度、精确、快速且适合自动化的方法。在消除慢性边缘性镁缺乏的情况下，通过直接法评估并以每升压积细胞中毫摩尔数表示的ErMg正常值为2.3±0.24。电感耦合等离子体质谱法（ICP-MS）是一种多元素分析技术。粒子诱导X射线发射（PIXE）也具有多元素分析能力，但耗时且成本高。微电极是细胞内Mg2+测量的金标准。但微电极和荧光探针测量的是镁离子的活性，而非浓度。人体完整红细胞的游离镁含量主要通过核磁共振法和零点滴定法进行评估。通过核磁共振（31P NMR法）估计的游离镁浓度为每升细胞水0.20±0.02毫摩尔，通过零点滴定法为0.55±0.12。由于红细胞内的镁在体内不断波动，目前用于游离镁测定的两种技术存在不确定性。游离镁仅占总镁的一小部分。有必要进一步研究以评估其变化在临床医学中的重要性。ErMg的外流通过膜性钠依赖性和钠非依赖性途径以及遗传和神经激素调节来控制。总ErMg或游离ErMg的变化不一定意味着镁池也会有类似变化。但它仍然是细胞内镁的基本静态指标。当它纳入动态镁研究的临床和辅助临床数据中时，其价值将得到提升。
