The electrolytes of muscle and liver in potassium-depleted rats.

The gross effects of withholding potassium from the diet of young rats has been the subject of a number of investigations (Osborne and Mendel, 1918; Miller, 1923; Leulier and Vanhems, 1934; Schrader, Prickett and Salmon, 1937; Grijns, 1938; Heppel and Schmidt, 1938). In general it was found that the deficiency results in failure to continue growth followed by death after a variable number of weeks. No reports are available in the literature dealing with chemical studies of the tissues of potassiumdepleted animals. The present investigation was designed to determine the effect of potassium deprivation on the concentration of the principal electrolytes in serum, muscle and liver tissue. In normal muscles the concentration of potassium is much greater than . that of sodium. It is generally held that potassium is concentrated inthe intracellular phase while sodium is largely restricted to the extracellular phase (see Fenn, 1936, and Manery and Hastings 1939). The most striking result of the work reported here lies in the fact that the muscles of animals deprived of potassium take up sodium instead of potassium. This occurs to such an extent that in some instances the muscles of the experimental animals are found to be richer in sodium than in potassium. We have here a clear-cut example of a condition in which sodium must occur largely as an intracellular cation.