Calcium-dependent aldosterone secretion in anephric and nonnephrectomized patients on regular hemodialysis.

The present study was undertaken to investigate the effect of a continuous calcium infusion on the plasma levels of aldosterone, renin activity, and cortisol in six anephric and four nonnephrectomized patients on regular hemodialysis. In both groups, a significant increase in whole blood ionized calcium (b-Ca2+) was demonstrated. A significant increase in plasma aldosterone (PAC) was noted in the nonnephrectomized patients, in whom the rise in PAC correlated with the increase in b-Ca2+. However, in the anephric patients only a smaller and insignificant increase in PAC was found. No significant changes were demonstrated in plasma cortisol or renin activity, nor in potassium or sodium concentrations in either group. It is concluded that ionized calcium influences the plasma levels of aldosterone in uremic patients on regular hemodialysis.