Na-K ATPase activity of erythrocyte membrane correlated with urinary Na/K ratio in normotensive adolescents with a family history of hypertension.

In female adolescents with a normal blood pressure range, the correlation between urinary sodium excretion and Na-K ATPase activity of erythrocyte membrane was investigated. 34 subjects with a family history of hypertension showed a significantly positive correlation between body mass index and mean blood pressure (r = 0.64, p less than 0.01), and a significantly lower urinary Na/Cr and Na/K ratio compared with 37 subjects without the same family history (p less than 0.05 and p less than 0.01, respectively). The positive correlation between urinary Na/K ratio and Na-K ATPase activity of erythrocyte membrane was demonstrated in only subjects with a family history of hypertension (r = 0.41, p less than 0.05). The authors discuss these significant correlations in terms of the abnormal membrane cation fluxes associated with essential hypertension.