Erythrocyte magnesium fluxes in mice with nutritionally and genetically low magnesium status

Low intracellular magnesium (Mg) contents may be observed in case of severe Mg insufficient intake or because of genetic regulation. This work was conducted to investigate the influence of intracellular Mg content on erythrocyte Mg2+ influx and efflux in mice with low nutritionally and genetically (MGL and MGH mice) Mg status. C57BL6 mice were fed for 2 wks a diet containing 1000 mg Mg/kg diet Mg ( control group), 100 mg Mg/kg diet (Mg-marginal group) or 30 mg Mg/kg diet (Mg-deficient group), while mice with low ( MGL) and high ( MGH) Mg levels were fed a control diet for 2 wks. The quantification of erythrocyte Mg2+ influx and efflux was performed using a stable isotope of Mg. Our results showed that erythrocyte Mg2+ influx and efflux were respectively increased and decreased in nutritional Mg deficiency; while in genetically determined Mg status Mg2+ fluxes were lower in MGL mice compared to MGH mice. Moreover Mg2+ efflux was significantly correlated to Mg level in erythrocytes in all the mice studied (p< 0.001). In conclusion, erythrocyte Mg2+ influx and efflux are modulated by low Mg status, namely decreased Mg2+ efflux compensate for nutritional Mg deficiency, while the genetic regulation of erythrocyte Mg2+ content depends on modification of Mg2+ influx.