The sodium, potassium, and water contents of red blood cells of healthy human adults.

Abstract
One hundred forty two subjects were studied. Red blood cell (RBC) Na concentration was found to be lower in young women than in middle-aged women or men. RBC [red blood cell] concentration was higher at all ages in women than in men. Ninety-one percent of the variation of RBC water content in young men was accounted for by the variation of RBC Na, K and hemoglobin concentrations. RBC Na and K concentrations in cell water were negatively correlated.