title: Effects of inhibition of nitric oxide synthase on systemic arterial pressure and renal vascular resistance in cats.
abstract: These studies were undertaken to examine the systemic and renal effects of the pharmacological inhibition of endothelium-derived nitric oxide (EDNO) in cats. In six healthy cats, the intravenous infusion of nitro-L-arginine at a dose of 100 micrograms kg-1 bodyweight min-1 resulted in a marked increase (P < 0.001) in mean arterial pressure from the control value of 116.7 +/- 4.6 mmHg to 154.2 +/- 6.8 mmHg and an increase (P < 0.05) in renal vascular resistance from the control value of 3.69 +/- 0.33 mmHg min ml-1 to 6.83 +/- 1.15 mmHg min ml-1. The increase in renal vascular resistance was generalised, with comparable increments in preglomerular and postglomerular vascular resistance. Mean values for glomerular capillary pressure (61.1 +/- 1.9 vs 61.9 +/- 1.6 mmHg), calculated from the sum of arterial colloid osmotic pressure plus proximal tubule stop-flow pressure, did not change in response to the infusion of nitro-L-arginine. However, there was a marked reduction in renal blood flow (29.4 +/- 3.1 to 16.9 +/- 2.3 ml min-1, P < 0.01) and glomerular filtration rate (5.22 +/- 0.57 to 3.52 +/- 0.45 ml min-1, P < 0.01). These results provide evidence that EDNO plays an important role in the basal regulation of systemic arterial blood pressure and renal haemodynamics in cats.
authors.affiliation: Department of Physiology and Pharmacology, College of Veterinary Medicine, University of Georgia, Athens 30602.
authors.forename: S A
authors.initials: SA
authors.lastname: Brown
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D002415:Cats / Q000502:physiology*; D007262:Infusions, Intravenous; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D014655:Vascular Resistance / Q000187:drug effects
chemical_list: D019335:Nitroarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases