Biological Role of Magnesium

Abstract Fersman (1934) commented on the relatively unimportant role of magnesium in biochemical processes. The comparatively limited radius of its ions, the stability and relative insolubility of its compounds prevent its taking an active part in the reactions of living matter. On the other hand, we have the statement of Vernadskii that in the plankton film of the ocean, in the ordinary accumulations and more massive growths, the amount of magnesium-containing chlorophyll must reach the order of 10-4 per cent by weight, if not higher, so that a small quantity of magnesium, entering into the composition of the chlorophyll-complex of the plankton, ultimately regulates the main part of the oxygenating function of living matter, the creation of free atmospheric oxygen. The material summarized by us likewise affords evidence of the importance of the role of magnesium in biological processes. All this, however, does not justify sharp differentiation between the biological role of magnesium and its role in biochemical processes. In all probability these processes are conditional to each other, although they are not identical processes. It is important to note the established and incontestable role of magnesium in many enzymatic processes in both the plant and animal kingdoms. The antagonistic action between magnesium and calcium, resulting from artificial changes in the ratios of these elements in soil, plants, and animals, can hardly occur under natural conditions, and, conversely, it must be assumed that a labile equilibrium between these elements is always maintained. The depressing action of magnesium ions on the central nervous system acquires considerable biological significance, since this permits the assumption that these ions in the animal organism may facilitate inhibitory processes in the nerve cell and insure the normal course of catabolic and anabolic processes. The narcotic and cholinolytic effects of magnesium constitute the basis for the wide therapeutic use of magnesium salts in medical practice.