Selective renal dopamine-1 receptor stimulation in man.
The selective dopamine-1 (DA-1) receptor agonist, fenoldopam, was studied during intravenous administration to ten normal male subjects on a diet of 150 mEq sodium and 60 mEq potassium per day to determine the mechanism of dopamine-induced natriuresis. During DA-1 receptor stimulation, urine flow rate and renal plasma flow manifested a biphasic increase. Urine flow rate increased from a control of 13 +/- 1 to 17 +/- 1.2 ml/min and again to a peak of 16 +/- 1. Renal plasma flow increased from 344 +/- 39 to 481 +/- 44 ml/min and then to 497 +/- 38. Sodium excretion (UNaV) and fractional sodium excretion (FENa) demonstrated a sustained increase. UNaV rose from a control of 0.21 +/- 0.03 to 0.32 +/- 0.05 mEq/min. FENa rose from a control of 1.6 +/- 0.1 to 2.7 +/- 0.6%. Fenoldopam did not alter glomerular filtration rate. The association of changes in renal plasma flow and in UNaV and FENa demonstrate in man that DA-1 receptor stimulation causes natriuresis by direct renal tubular action. The renal tubular effect appears to be a major determinant of the degree of natriuresis.
D000328:Adult; D000450:Aldosterone / Q000097:blood; D001552:Benzazepines / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D018818:Fenoldopam; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000187:drug effects*; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D009994:Osmolar Concentration; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000502:physiology; D012079:Renal Circulation / Q000187:drug effects; D012084:Renin-Angiotensin System / Q000187:drug effects; D012964:Sodium / Q000652:urine; D014563:Urodynamics / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*
D001552:Benzazepines; D011954:Receptors, Dopamine; D014665:Vasodilator Agents; D000450:Aldosterone; D012964:Sodium; D018818:Fenoldopam