Endothelin and endothelium-derived relaxing factor control of basal renovascular tone in hydronephrotic rat kidneys.
1. In order to investigate the control of renal vascular tone by endothelin (ET) and endothelium-derived relaxing factor (EDRF) under basal conditions, we infused intravenously anti-ET-1/3 antibodies (a-ET-1/3) and NG-nitro-L-arginine methyl ester (L-NAME) in split hydronephrotic rat kidneys. 2. A 25 min I.V. infusion of a-ET-1/3 (4.0 x 10(-13) mol kg-1 min-1) induced a time-dependent vasodilatation of arcuate (16.5%) and interlobular arteries (18.6%) as well as an increase of glomerular blood flow (GBF) by 32%. 3. Inhibition of EDRF synthesis by L-NAME produced a marked vasoconstriction of arcuate arteries (17.1%) and efferent (20.1%) arterioles and a decrease of GBF by 43%. 4. Co-infusion of a-ET-1/3 and L-NAME induced efferent vasoconstriction by 19.5%, whereas preglomerular vessel diameters remained unchanged. 5. The specificity of a-ET-1/3 effects was confirmed by simultaneous I.V. application of a-ET-1/3 and ET-1 (160 ng I.V.) which produced no significant vascular effects. Injection of ET-1 alone constricted arcuate arteries and decreased glomerular blood flow by 25%. 6. Experiments in normal rat kidneys with a-ET-1/3 I.V. revealed an increase of renal blood flow by 21%. 7. Our results demonstrate a physiological control of basal vascular tone in larger preglomerular arterioles by ET and EDRF. Efferent arteriolar tone is predominantly controlled by EDRF.
Gulbins
E
E
I. Institute of Physiology, University of Heidelberg, Germany.
Hoffend
J
J
Zou
A P
AP
Dietrich
M S
MS
Schlottmann
K
K
Cavarape
A
A
Steinhausen
M
M
D000818:Animals; D000906:Antibodies / Q000276:immunology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001160:Arterioles / Q000502:physiology; D016232:Endothelins / Q000276:immunology / Q000502:physiology*; D005260:Female; D006869:Hydronephrosis / Q000503:physiopathology*; D066298:In Vitro Techniques; D007668:Kidney / Q000503:physiopathology*; D007678:Kidney Glomerulus / Q000098:blood supply; D009129:Muscle Tonus / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D000906:Antibodies; D016232:Endothelins; D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester