RELATIONSHIPS OF SODIUM AND POTASSIUM 

 TO CARBOHYDRATE METABOLISM 



DURING the past few years an increasing number of investigators have called 

 attention to the possibility of interrelationships between the monovalent 

 elements, sodium and potassium, and carbohydrate metabolism. However, no 

 effort has as yet been made to correlate the results of experiments carried out 

 from many different angles and no place has been given to the subject even 

 in the latest monographs or textbooks on physiology. The present review 

 represents an attempt to summarize and evaluate pertinent data from widely 

 scattered sources, special reference being made to reports concerning the an- 

 tagonistic effects of sodium and potassium on carbohydrate metabolism in 

 diabetes mellitus. 



Relationship of Sodium to Carbohydrate Metabolism 



The first suggestion that mammalian carbohydrate metabolism might be 

 influenced by the administration of sodium salts was the observation by 

 Murlin and Kramer^ that sodium hydroxide and sodium carbonate increased 

 the utilization of glucose by depancreatized dogs. Murlin and Graver" and 

 UnderhilP subsequently reported marked decreases in glycosuria in diabetic 

 patients following administration of these alkaline salts in liberal amounts. 

 The effects observed were attributed to induced changes in the acid-base 

 equilibrium of the body toward the alkaline side. 



Subsequent studies on the effects of changes in the acid-base balance on 

 carbohydrate metabolism, however, have been somewhat contradictory. For 

 instance. Beard* reported finding little or no effect from giving moderate 

 amounts of sodium bicarbonate to diabetics but incidentally recorded the 

 fact that two of his patients, who voluntarily took increased amounts of 

 sodium chloride and water, showed increases in their carbohydrate tolerance. 

 He drew no conclusions from these observations. Thompson, Mitchell and 

 Kolb" found in normal subjects that acid administration was followed by 

 diminution of carbohydrate tolerance as indicated by blood-sugar curves, 

 while alkalosis had little effect. In a series of acute experiments on normal 

 children, Johnston and Maroney" found the oxidation of dextrose to be ac- 

 celerated by a slight shift toward the acid side of neutrality but depressed by 

 marked acidosis. It was inhibited on the alkaline side. They also found that 

 the oxidation of dextrose was at first depressed but later accelerated by in- 

 gestion of NaCl and water. It would appear from these conflicting residts that 

 acid-base balance per se plays little or no direct role in carbohydrate metabo- 

 lism. 



Schenk,^ who investigated the effects of intravenous administration of vari- 

 ous electrolytes on blood sugar, found that the latter was decreased signifi- 



[413] 



