On magnesium and contractile tissues

Abstract

The experiments reported extend and confirm the findings of Meltzer and Auer. Magnesium is found to have a direct inhibitory effect on automatic tissue (plain and cardiac muscle) and a depressing effect upon the irritability of the non-automatic striped muscle. This influence is slow to wear off after the application but seems generally to favor the later activity of the muscle — in other words, it is conserving in character. Magnesium appears to be the element to which we may look with most reason when seeking an agent that shall suspend katabolic changes without permanently damaging living structures. It is clearly less hurtful than potassium in like concentration. Comparison of magnesium with potassium shows that the former is not so distinctly the antagonist of calcium as is the latter. It also seems probable that the power to mediate vagus inhibition which Howell fixed upon potassium is a unique property of that element and not shared by magnesium.