Radiocontrast-induced natriuresis associated with increased urinary urodilatin excretion.
OBJECTIVE
Intravascular radiocontrast agents induce a pronounced diuresis. The aim of the present study was to investigate the (patho-)physiological mechanisms of the radiocontrast-induced diuresis.


METHODS
The fractional excretion of sodium, the urinary excretion of the renal natriuretic peptide urodilatin and the plasma concentration of atrial natriuretic peptide were measured in 42 unselected patients immediately before and after intravascular radiocontrast administration during coronary angiography.


METHODS
Cardiac catheterization laboratory of a university hospital.


RESULTS
After angiography both the plasma concentration of atrial natriuretic peptide (median post-pre difference: 3.9 pmol L(-1), quartiles -1.2; 7.0) and the urinary excretion of urodilatin (median post-pre difference: 67.0 nmol urodilatin/mol creatinine, quartiles 39.7; 152.1) were increased. The urinary urodilatin excretion was correlated with an increase in the fractional excretion of sodium (median post-pre difference: 1.7%, quartiles 0.6; 3.1). There was no correlation between the serum concentration of atrial natriuretic peptide and urinary sodium excretion. For the radiocontrast-induced increase in both urodilatin and sodium excretion there was no indication for differences between patients without (31) and with (11) intravenous saline infusion.


CONCLUSIONS
The radiocontrast-induced diuresis is a natriuresis which is associated with an increased urinary excretion of urodilatin. The association between natriuresis and urinary urodilatin excretion irrespective of baseline volume status corroborates the hypothesis that urodilatin contributes to the sodium excretion after radiocontrast administration in a paracrine manner. This finding has pathophysiological and potentially therapeutic implications in radiocontrast-induced nephropathy.
Haller
C
C
Department of Medicine and Institute of Medical Statistics, University of Heidelberg, Germany. challer@krzmail.krz.uni-heidelberg.de
Meyer
M
M
Scheele
T
T
Koch
A
A
Forssmann
W G
WG
Kübler
W
W
D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000652:urine*; D006328:Cardiac Catheterization; D003287:Contrast Media / Q000494:pharmacology*; D017023:Coronary Angiography; D006801:Humans; D008875:Middle Aged; D009318:Natriuresis / Q000187:drug effects*; D010446:Peptide Fragments / Q000652:urine*; D019275:Radiopharmaceuticals / Q000494:pharmacology*
D003287:Contrast Media; D010446:Peptide Fragments; D019275:Radiopharmaceuticals; C056452:Ularitide; D009320:Atrial Natriuretic Factor