Enhancement of norepinephrine and angiotensin II-induced renal effects by NG-nitro-L-arginine, a nitric oxide synthase inhibitor.
We investigated whether endogenous nitric oxide (NO) has a role as an inhibitory modulator of norepinephrine (NE)- and angiotensin II (Ang II)-induced renal effects in anesthetized dogs. Intrarenal arterial infusion of NE (100 ng/kg/min) or Ang II (10 ng/kg/min) decreased renal blood flow (RBF), glomerular filtration rate (GFR) and urine formation. The NE- or Ang II-induced renal effects were augmented by the intrarenal administration of a NO synthase inhibitor, NG-nitro-L-arginine (NOARG), at doses (10 and 40 micrograms/kg/min) which did not affect the mean arterial blood pressure and heart rate. The stimulating activity of NOARG on NE- or Ang II-induced renal effects were abolished by the simultaneous administration of L-arginine, a NO precursor. These findings suggest that endogenous NO, which is probably generated within the kidney, functions as an inhibitory modulator in NE- or Ang II-induced renal vasoconstriction and antidiuresis.
Matsumura
Y
Y
Department of Pharmacology, Osaka University of Pharmaceutical Sciences, Japan.
Egi
Y
Y
Maekawa
H
H
Miura
A
A
Murata
S
S
Morimoto
S
S
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000758:Anesthesia; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003714:Denervation; D004285:Dogs; D004357:Drug Synergism; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D007668:Kidney / Q000187:drug effects* / Q000294:innervation; D007677:Kidney Function Tests; D008297:Male; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D009638:Norepinephrine / Q000494:pharmacology*; D012079:Renal Circulation / Q000187:drug effects
D000804:Angiotensin II; D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009638:Norepinephrine