STIMULATION OF MITOTIC ACTIVITY AND INITIATION OF DEOXYRIBONUCLEIC ACID SYNTHESIS IN POPULATIONS OF RAT THYMIC LYMPHOCYTES BY MAGNESIUM

The progression of rat thynocytes (maintained in vitro) into mitosis is profoundly affected by the level of magnesium in the medium. Increasing the extracellular MgC12 concentration from 0 to 1.0 mM does not affect mitotic activity, but a further increase to 1.2 and 2.5 mM rapidly and strongly stimulates the flow of cells into mitosis. The level of extracellular magnesium also governs the mitogenic effectiveness of calcium ions. The mitogenic action of magnesium stems from an ability to stimulate the initiation of deoxyribonucleic acid synthesis. Copyright © 1969 Wiley‐Liss, Inc.