Sodium transport in erythrocytes: differences between normal children and children with primary and secondary hypertension.

The following measurements were made in normal children, children with primary hypertension, and children with secondary hypertension: erythrocyte intracellular sodium concentration, total sodium efflux rate constant, and maximum binding of ouabain to erythrocytes reflecting the number of sodium/potassium adenosine triphosphatase pump sites. Children with primary hypertension had a significantly higher mean erythrocyte intracellular sodium concentration (8.2 compared with 6.6 and 6.7 mmol/l cells), and significantly lower total sodium efflux rate constant (0.5071 compared with 0.6983 and 0.6197) and maximum binding of ouabain to erythrocytes (9.1 compared with 11.7 and 11.0 nmol/l cells) than normal children and children with secondary hypertension, respectively.