Prolonged administration of human atrial natriuretic peptide in healthy men: evanescent effect on diuresis in spite of simultaneous infusion of norepinephrine

In healthy, sodium and fluid replete men (n = 6) a transient increase in diuresis is seen during the prolonged infusion of human atrial natriuretic peptide (hANP: 50 micrograms h-1 for 6 h). In order to evaluate whether this evanescent diuretic effect of hANP is due to the peptide's hypotensive action, the latter was compensated for by the concomitant infusion of norepinephrine (NE: 50 ng kg-1 min-1). The decrease in hANP-induced diuresis towards the end of the 6-h infusion was not prevented by the additional infusion of norepinephrine, which also failed to influence hANP-stimulated natriuresis. Plasma concentrations of hANP, which were continuously elevated to about double of basal concentrations during the infusion of hANP, were not affected by exogenous norepinephrine. These data demonstrate that the transient character of hANP-induced diuresis cannot be offset by counterbalancing the peptide's hypotensive effect.