Magnesium Transport in Humans with Hypomagnesemia

The kinetics of radiomagnesium exchange were measured in 9 human subjects with moderate hypomagnesemia and 1 normomagnesemic patient with demonstrated magnesium deficiency. Eight of the 10 patients were alcoholics with associated hepatic dysfunction and disturbances in the plasma concentrations of other electrolytes as well as hypomagnesemia. Three normomagnesemic patients with alcoholism and hepatic cirrhosis were also studied. A digital computer program utilizing a parallel 3-compartment open model of magnesium exchange was employed for quantitation of the primary data. At the time of study, 2–9 weeks after hospital admission, normal kinetics of magnesium exchange were found in almost all subjects. The data also indicated that conventionally calculated apparent exchangeable body pools of magnesium show a borderline correlation with computer derived values for the exchangeability of magnesium and are therefore not reliable parameters of magnesium turnover. Despite moderate hypomagnesemia and/or magnesium deficiency, the data suggest that cell membranes retain their ability to exert a control over the cellular transport of magnesium and continue to regulate the intracellular concentrations of magnesium.