Cation imbalance in erythrocytes, serum and 24-hour urine from patients with essential hypertension and adolescents with high blood pressure.

Electrolyte concentrations in the erythrocytes, serum and 24-hr urine were measured in 34 untreated essential hypertensives (EH), 32 normotensives with a family history of hypertension (N+), 112 normotensives without a family history of hypertension (N-), 76 senior high school students with high blood pressure (H) and 110 students with normal blood pressure (C). For the measurement of intra-erythrocyte electrolytes, a new method to decrease the trapped plasma was developed and adopted. A new simple method to collect 24-hr urine was devised, too. The results were as follows: 1) The sodium concentration [Na] and the ratio of [Na] to potassium concentration [Na/K] in the erythrocytes were significantly higher in the EH and N+ than in the group of N- (p less than 0.01). 2) There was a positive correlation (r = 0.43) between the [Na/K] in the serum and erythrocytes in the 3 groups. The [Na/K] value in the erythrocytes to a given [Na/K] value in the serum was higher in EH than in the group of N-. 3) When the group of H was compared with C, the Na excretion of the 24-hr urine in the former group was found to be slightly higher, and the [Na/K] of the 24-hr urine and the [Na] and [Na/K] values of the erythrocytes were significantly higher, too. It may therefore be said that an increase in the intracellular [Na] or [Na/K], which may be caused genetically, and an excess of Na intake and an increase of the ratio of Na/K intake are presumed to play an important role in the pathogenesis of essential hypertension.