A modification of the magnesium ammonium phosphate precipitation method for the determination of serum magnesium was devised to determine the magnesium content of erythrocytes.
The concentration of magnesium in the red cells of healthy hospital personnel was 4.67 ± 0.92 mEq./L.
An increase in erythrocyte magnesium concentration was observed in patients with reticulocytosis. Experimental production of reticulocytosis by the administration of phenylhydrazine to rabbits confirmed these clinical observations.
No significant in vitro uptake of Mg28 from the suspending medium occurred in mature human erythrocytes or in mature or immature erythrocytes from rabbits.
The relative tissue uptake of Mg28 in the bone marrow was significantly increased in animals in whom anemia and marked reticulocytosis were produced by phenylhydrazine. Relative activity was decreased in the hearts, spleens, and kidneys of these animals.
Since there is no evidence for significant exchange of magnesium in immature or mature erythrocytes in the peripheral circulation, it is concluded that the magnesium content of erythrocytes is increased in the bone marrow prior to their release into the peripheral circulation.