[A close relationship between the renal potassium regulation and the maximum binding of ouabain to erythrocytes].

Maximum binding of ouabain to erythrocytes (Bmax), serum K, urinary aldosterone excretion (U-Aldo) and fractional excretion of filtered K (FEK) were examined in 69 healthy children aged 12 to 15 years to assess the relationship between the sodium pump receptor in erythrocytes and the renal handling of potassium (K). Bmax showed a significant negative correlation with FEK. Subsequently, FEK showed a negative correlation with serum K which was within normal range in every child, and a positive correlation with U-Aldo. However, Bmax showed no correlation with serum K or U-Aldo. These findings suggest that aldosterone may influence Bmax via the changes in FEK and serum K within physiological ranges. In other words, there can exist a close relation between Bmax and the renin-angiotensin-aldosterone system through K metabolism.