Intracellular magnesium and magnesium buffering

The development of new techniques for measuring intracellular free Mg²⁺ during the 1980s has provided investigators with the tools needed to produce new insights into the regulation of cellular magnesium. Within the limits of this technology, it appears that all mammalian cells maintain free cytosolic Mg²⁺ levels within the fairly narrow range of 0.25–1 mM. While transport mechanisms and sequestration within cellular organelles will contribute to this regulation, it is binding of Mg²⁺ to an as yet poorly defined system of buffers that is largely responsible for determining the set point of this regulation. The lack of an adequately Mg²⁺-selective ionophore remains an impediment to progress in this area.