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Hypertension, Vol 10, 43-54, Copyright © 1987 by American Heart Association
Z Gluck, L Jossen, P Weidmann, MP Gnadinger and E Peheim
Whether the dopaminergic system may be involved in essential hypertension
is of pathogenetic as well as therapeutic interest. Therefore, we
investigated in eight hypertensive and 12 normal subjects cardiovascular,
endocrine, and renal responses to fenoldopam, which has been characterized
experimentally as an agonist of peripheral postsynaptic dopamine1
receptors. A single oral dose of fenoldopam, 100 mg, changed blood pressure
(BP) in hypertensive subjects (from 163/103 to 147/76 mm Hg; p less than
0.01 for systolic and p less than 0.001 for diastolic BP) and normal
subjects (from 121/81 to 123/65 mm Hg; p less than 0.001 for diastolic BP);
percentage decreases in diastolic BP averaged -20 +/- 6 and -16 +/- 7%,
respectively. Fenoldopam-induced effects on other variables were similar in
the two groups. Heart rate rose (p less than 0.001) on average from 69 to
92 beats/min in hypertensive and from 64 to 84 beats/min in normal
subjects. Effective renal plasma flow increased (from 552 to 765 and 634 to
937 ml/min/1.73 m2; p less than 0.01), while glomerular filtration rate
tended to decrease (from 121 to 99 ml/min/1.73 m2 in the hypertensive and
from 119 to 97 ml/min/1.73 m2; p less than 0.001 in the normal group).
Fractional sodium clearance was elevated (from 2.8 to 5.2 and 1.7 to 3.8%;
p less than 0.01), as was free water clearance (from -1.7 to 0.6 and -1.7
to 0.1 ml/min/1.73 m2; p less than 0.01). Potassium clearance was largely
unchanged. Plasma renin activity increased about twofold (p less than 0.01
in normal subjects), and plasma aldosterone by 40% (NS). Plasma
norepinephrine levels increased twofold to 2.5-fold (p less than 0.001),
and urinary norepinephrine excretion fivefold to 10-fold (p less than
0.01). Fenoldopam-induced changes were not significantly modified by
intravenous and/or oral pretreatment with the dopamine- receptor antagonist
metoclopramide or the cyclooxygenase inhibitor indomethacin. These findings
suggest that in humans, fenoldopam may acutely override the dopaminergic
antagonism of metoclopramide given in clinical dosage and that its
cardiovascular and renal effects are not prostaglandin-mediated. Although
acute sympathetic stimulation may be partially antagonistic, the
concomitant BP-lowering, renal vasodilating, and natriuretic actions of
fenoldopam represent a desirable profile of a potential antihypertensive
agent.
ARTICLES
Cardiovascular and renal profile of acute peripheral dopamine1-receptor agonism with fenoldopam
This article has been cited by other articles:
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M. B. Murphy, C. Murray, and G. D. Shorten Fenoldopam -- A Selective Peripheral Dopamine-Receptor Agonist for the Treatment of Severe Hypertension N. Engl. J. Med., November 22, 2001; 345(21): 1548 - 1557. [Full Text] [PDF] |
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