Hypertension, Vol 20, 80-84, Copyright © 1992 by American Heart Association
Atrial natriuretic factor influences renal diurnal rhythm in essential hypertension
WM Janssen, D de Zeeuw, GK van der Hem and PE de Jong
Department of Medicine, University Hospital of Groningen, The Netherlands.
We investigated in six patients with essential hypertension the effect of a
low dose atrial natriuretic factor infusion for 5 days on the diurnal
rhythm of renal electrolyte excretion. Atrial natriuretic factor infusion
increased the net excretion of sodium and caused a delay in its time of
maximal diurnal urinary excretion. Similarly, atrial natriuretic factor
caused an increase in the net excretion of chloride, calcium, and magnesium
and also changed the diurnal rhythms of these electrolytes. In contrast,
atrial natriuretic factor did not change the net excretion of potassium,
phosphate, and uric acid, nor did atrial natriuretic factor change the
diurnal rhythms of these solutes. During baseline, the time points of
maximal urinary excretion of sodium and potassium overlapped, whereas
atrial natriuretic factor infusion caused sodium excretion to peak 2.2 +/-
0.3 hours (p less than 0.02) after the potassium excretion peak. During
baseline, the time of maximal urinary excretion of sodium did not correlate
with the time of highest blood pressure, whereas it correlated negatively
with mean plasma aldosterone concentration. In contrast, during atrial
natriuretic factor infusion the time of maximal urinary excretion of sodium
correlated positively with the time of highest blood pressure, whereas it
did not correlate with mean plasma aldosterone concentration. These data
suggest that atrial natriuretic factor is involved with the diurnal rhythm
of the urinary excretion of sodium and that atrial natriuretic
factor-induced natriuresis is mediated in part by blood pressure and plasma
aldosterone.