AJP - Renal Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Renal Physiol 258: F627-F635, 1990;
0363-6127/90 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Pollock, D. M.
Right arrow Articles by Arendshorst, W. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pollock, D. M.
Right arrow Articles by Arendshorst, W. J.

AJP - Renal Physiology, Vol 258, Issue 3 627-F635, Copyright © 1990 by American Physiological Society

ARTICLES

Tubuloglomerular feedback and blood flow autoregulation during DA1-induced renal vasodilation

D. M. Pollock and W. J. Arendshorst
Department of Physiology, University of North Carolina, Chapel Hill 27599-7545.

The effect of renal vasodilation produced by the dopamine DA1-receptor agonist, fenoldopam (SKF-82526), on tubuloglomerular feedback (TGF) activity and the autoregulation of renal blood flow (RBF) was determined in euvolemic rats. Fenoldopam (2.5 micrograms.kg-1.min-1 iv) increased RBF by 17% (electromagnetic flow probe) while glomerular filtration rate (GFR) was unchanged; mean arterial pressure was decreased by 6%. Superficial cortical blood flow was increased by 12% (laser-Doppler flowmetry) while single-nephron GFR (SNGFR) and estimated glomerular capillary pressure (stop-flow pressure, Psf) were stable. SNGFR measured at proximal and distal sites along the same nephron was not affected by fenoldopam. Partial inhibition of TGF was indicated by the constancy of distal SNGFR and the proximal-distal SNGFR difference in the presence of increased distal delivery of native fluid. However, fenoldopam did not affect feedback control of Psf evaluated by perfusing artificial fluid through Henle's loop at 0-62 nl/min. Despite the decrease in renal vascular resistance over an arterial pressure range of 130 to 70 mmHg, RBF was autoregulated efficiently during fenoldopam infusion. These results indicate that DA1-receptor activation dilates the preglomerular and efferent arterioles without affecting GFR or glomerular pressure. However, this vasodilatory mechanism operates independent of autoregulation and TGF-induced changes in glomerular pressure such that preglomerular vessels remain responsive to the appropriate signals from these intrinsic control systems. The ability of fenoldopam to blunt feedback control of SNGFR may depend on changes in the filtration coefficient independent of glomerular pressure and/or a constituent of natural tubular fluid.


This article has been cited by other articles:


Home page
 NEJMHome page
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]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online