M. Vanburen et al., NATRIURETIC AND KALIURETIC RESPONSE TO POTASSIUM LOAD - MODULATION BYSODIUM-INTAKE, Nephrology, dialysis, transplantation, 8(6), 1993, pp. 495-500
Potassium (K) loading is followed by a rapid increase in sodium (Na) a
nd K excretion. To evaluate the influence of Na intake on this effect,
we studied the acute natriuretic and kaliuretic response to a single
oral K load (100 mmol) in six healthy volunteers equilibrated on a 10-
, 100-, and 400-mmol Na intake. Compared to the 100-mmol Na intake, th
e 400-mmol Na intake greatly enhanced the natriuretic effect of the K
load; during the 10-mmol Na intake no natriuresis but even some Na ret
ention occurred. The kaliuretic effect was not significantly changed a
nd occurred at similar values of plasma K. Plasma aldosterone was supp
ressed during the 400-mmol Na diet and stimulated during the 10-mmol N
a diet, but the relative increments after the Kcl load did not differ
among the three diets. In conclusion, whereas the effect of a K load o
n kaliuresis is relatively independent of Na intake, its effect on Na
excretion varies from marked natriuresis to slight Na retention. The N
a retention is probably due to acute K-induced aldosterone stimulation
, and the natriuresis to K-induced increase in distal Na delivery not
utilized to promote K excretion. Apparently, the integration of renal
Na and K handling after a K load is such that K balance is maintained
at the cost of Na balance.