ABSTRACT
For the purpose of elucidating relation between red cell electrolyte concentrations and serum digoxin level, measurement of red cell electrolyte concentrations and seum digoxin level by radioimmunoassay were done in 46 normal controls and 63 patients of CHF including 8 patients with digitalis intoxication. The results obtained were as follows: 1. Red cell sodium concentration and ratio of red cell sodium to red cell potassium concentration in normal males were significantly higher than those of females, and red cell potassium concentration in normal males was significantly lower than that of normal females. 2. Red cell potassium concentration in patients of CHF was significantly higher than that of normal controls, but there was no difference in the red cell sodium concentration between the groups. 3. There was no relation between red cell electrolyte concentrations and serum digoxin level, and red cell electrolyte concentration did not exactly estimate serum digoxin level. 4. Red cell electrolyte concentrations in the patient of CHF were valuable in detecting digitalis toxicity.