Role of endothelium-derived relaxing factor in the maintenance of renal blood flow in a rodent model of chronic hydronephrosis.
OBJECTIVE
To define the role of endothelium-derived relaxing factor (EDRF) in the regulation of renal hemodynamics in the hydronephrotic kidney.


METHODS
Experiments were performed in control rats and in rats that had undergone unilateral ureteral ligation 6 weeks before. Renal blood flow was monitored before and after inhibition of EDRF synthesis in the control and hydronephrotic animals. Videomicroscopy was also performed in hydronephrotic animals to observe directly the effect of inhibition of EDRF synthesis on the renal microcirculation.


RESULTS
Inhibition of EDRF synthesis resulted in a 61% decrease in renal blood flow in the control animals compared with only a 27% decrease for the hydronephrotic animals. The videomicroscopy studies demonstrated that inhibition of EDRF synthesis results in significant vasoconstriction of the preglomerular and postglomerular resistance vessels.


CONCLUSIONS
Although EDRF continues to play a significant role in the maintenance of renal blood flow in the chronically obstructed kidney, EDRF synthesis by the renal vascular endothelium may be reduced in this setting, contributing to ischemic renal atrophy.
Chen
R N
RN
Department of Urology, Cleveland Clinic Foundation, OH 44195, USA.
Inman
S R
SR
Stowe
N T
NT
Novick
A C
AC
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002908:Chronic Disease; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D006869:Hydronephrosis / Q000503:physiopathology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D018715:Microscopy, Video; D009569:Nitric Oxide / Q000096:biosynthesis / Q000502:physiology*; D019335:Nitroarginine; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000187:drug effects / Q000502:physiology*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology
D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D000109:Acetylcholine