Renal blood flow changes induced with endothelin-1 and fenoldopam mesylate at quantitative Doppler US: initial results in a canine study.
OBJECTIVE
To evaluate quantitative Doppler ultrasonography (US) for assessing renal blood flow changes induced with endothelin-1 (ET-1) and fenoldopam mesylate in conscious dogs.


METHODS
A blood flow probe was surgically implanted around the renal artery in eight adult dogs. Color and power Doppler US images were acquired in conscious restrained dogs during intravenous infusion of ET-1 and fenoldopam mesylate. Simultaneous with imaging, blood flow through the renal artery was measured with the implanted probe. The color level of the images within the region representing the kidney was analyzed to derive flow indices. These indices were compared with direct-flow measurements.


RESULTS
The flow indices, color-weighted flow area (CWFA), and percentage of area of color, derived from color and power Doppler US images, correlated linearly with direct flow. The mean color level of color and power Doppler US images correlated weakly with direct flow. Pre- versus postinfusion CWFA decreased with all ET-1 infusions (P < or =.032). Infusion of fenoldopam mesylate increased CWFA in all cases (P < or =.032).


CONCLUSIONS
Quantitative Doppler US enabled successful measurement of the flow changes induced with ET-1 and fenoldopam mesylate. Quantitative Doppler US is potentially useful as a noninvasive surrogate endpoint in evaluating the action of various therapeutic agents.
Sehgal
C M
CM
Department of Radiology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA 19104-6086, USA. sehgal@oasis.rad.upenn.edu
Arger
P H
PH
Silver
A C
AC
Patton
J A
JA
Saunders
H M
HM
Bhattacharyya
A
A
Bell
C P
CP
D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D004285:Dogs; D019332:Endothelin-1 / Q000494:pharmacology*; D018818:Fenoldopam / Q000494:pharmacology*; D008297:Male; D012079:Renal Circulation / Q000187:drug effects*; D018608:Ultrasonography, Doppler; D018615:Ultrasonography, Doppler, Color; D014662:Vasoconstrictor Agents / Q000494:pharmacology*; D014665:Vasodilator Agents / Q000494:pharmacology*
D000959:Antihypertensive Agents; D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D018818:Fenoldopam