Effect of potassium chloride on plasma renin activity and plasma aldosterone during sodium restriction in normal man.

The present study was designed to evaluate the spectrum of responses of PRA and plasma aldosterone (PAldo) to a range of oral potassium intakes (0 to 300 mEq of potassium chloride per day) in 20 normal human subjects receiving an electrolyte-free diet. Potassium exhibited a dose-dependent natriuretic effect. The results of the PRA studies indicate that normal dietary amounts (50 mEq/day) of potassium chloride do not prevent the increase in PRA with absolute sodium deprivation and that PRA is maximally stimulated on 150 mEq of potassium chloride per day. The rise in PRA is directly correlated with serum potassium concentration. The results of the PAldo studies indicate that potassium chloride deprivation attenuates PAldo increases due to sodium deprivation and that PAldo is maximally stimulated on 150mEq of potassium chloride per day. The rise in PAldo is directly correlated with serum potassium concentration and with PRA. The administration of 300 mEq/day of potassium chloride caused significant hyperkalemia and blunted both PRA and PAldo increases. Our results suggest that potassium chloride has an important role in the regulation of PRA and PAldo, and that only following potassium chloride deprivation is the PRA/PAldo response dissociated.