Sodium and calcium in lymphocytes and erythrocytes in essential hypertension.

The present study compared protein-related sodium concentrations in lymphocytes with the sodium and calcium activities in erythrocytes from 12 untreated patients with essential hypertension and 15 normal control subjects. It appeared that protein-related Na+ in lymphocytes was elevated about threefold in essential hypertensives. Comparable increases were also noted in intracellular Na+ and Ca2+ activities. The correlation between Na+ in lymphocytes and in erythrocytes was not close. These results suggest that the determination of protein-related Na+ in lymphocytes discriminates between normotensives and essential hypertensives as well as measurements of ion activities in erythrocytes. Altered intracellular ion binding may be partly responsible for the changes in intracellular protein-related Na+.