Myocardium and Plasma Electrolytes in Dietary Magnesium and Potassium Deficiency in the Rat

Abstract

Deficiencies in the diet of magnesium and of potassium were studied in young growing rats. The metabolism of magnesium and potassium are interrelated, and factors affecting this interrelationship are reviewed. A deficiency of magnesium in the diet produced a decrease in cardiac muscle potassium and plasma potassium, a decrease in plasma magnesium (two of three experiments), and a decrease in muscle magnesium (one of two experiments). Dietary potassium deficiency produced an unexpected increase in plasma magnesium, a decrease in cardiac muscle magnesium and a decrease in cardiac muscle and plasma potassium. From our experiments and from the work of others we conclude that a dietary deficiency of either magnesium or potassium produces a decrease in the concentration of these ions in cardiac muscle and in plasma. The one exception is that of an increase in plasma magnesium with dietary potassium deficiency. The hypothesis that these interrelationships are related to reactions involving energy production and ultilization is considered likely.