The effect of selective dopamine-1 receptor stimulation on renal and adrenal function in man.
We studied the actions of iv fenoldopam, a selective dopamine-1 (DA-1) receptor agonist, in 10 normal men eating a diet containing 150 meq sodium and 60 meq potassium per day. During DA-1 receptor stimulation systemic hemodynamic function did not change. Fenoldopam resulted in an increase in urine flow rate from 13 +/- 1 (+/- SE) to a peak of 17 +/- 2 mL/min (P less than 0.05) and an increase in renal plasma flow from 344 +/- 39 to 481 +/- 44 mL/min (P less than 0.05). Urinary sodium excretion and fractional excretion of sodium both increased. Urinary sodium excretion rose to a maximum of 0.32 +/- 0.05 compared with a control value of 0.21 +/- 0.03 meq/min (P less than 0.01), while fractional excretion of sodium rose to 2.7 +/- 0.6 compared with a control value of 1.6 +/- 0.1% (P less than 0.05). The glomerular filtration rate did not change. Administration of a predominantly DA-2 antagonist during continuous DA-1 receptor stimulation did not block the fenoldopam-induced natriuresis. The rise in plasma aldosterone concentration after metoclopramide administration was blunted by DA-1 receptor activation [19.2 +/- 2.9 during control compared with 12.7 +/- 1.3 ng/dL (P less than 0.01) during fenoldopam]. No change occurred in serum potassium, plasma cortisol, or PRA. We conclude that selective DA-1 receptor stimulation in man produces sustained natriuresis and inhibition of aldosterone release by direct renal and adrenal effects.
D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D001552:Benzazepines / Q000494:pharmacology; D018818:Fenoldopam; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008787:Metoclopramide / Q000494:pharmacology; D009318:Natriuresis / Q000187:drug effects; D011188:Potassium / Q000008:administration & dosage; D011954:Receptors, Dopamine / Q000378:metabolism*; D012982:Sodium, Dietary / Q000008:administration & dosage; D014554:Urination / Q000187:drug effects
D001552:Benzazepines; D011954:Receptors, Dopamine; D012982:Sodium, Dietary; D018818:Fenoldopam; D008787:Metoclopramide; D011188:Potassium