title: Nitric oxide and renal effects of volume expansion in conscious monkeys.
abstract: Experiments were performed to determine the effects of nitric oxide (NO) synthase inhibition on the renal responses to volume expansion in conscious cynomolgus monkeys. All animals were volume expanded with 3% dextran in normal saline under three conditions: 1) during a control state, 2) during constant infusion of the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME, 30 microg x kg(-1) x min(-1)), and 3) during simultaneous infusion of L-NAME and excess NO substrate L-arginine (0.6 mg x kg(-1) x min(-1)). The control volume expansion increased urine flow from 0.27 +/- 0.05 to 0.94 +/- 0.28 ml/min and sodium excretion from 21 +/- 9 to 95 +/- 26 microeq/min. During L-NAME infusion, these responses were attenuated in that urine flow only increased from 0.13 +/- 0.03 to 0.28 +/- 0.09 ml/min and sodium excretion from 13 +/- 8 to 35 +/- 23 microeq/min. Addition of L-arginine to the L-NAME infusion abolished these renal excretory effects of L-NAME alone. With combined L-NAME/L-arginine, volume expansion increased urine flow from 0.37 +/- 0.23 to 1.09 +/- 0.23 ml/min and sodium excretion from 38 +/- 27 to 150 +/- 24 microeq/min, responses similar to control. L-Arginine also markedly attenuated the effect of L-NAME to increase mean arterial pressure and abolished the L-NAME decreases in creatinine and p-aminohippurate clearances. However, an L-NAME-induced bradycardia could only be partially reversed. These results demonstrate that a functioning NO system may be important in mediating normal renal responses to volume expansion in this primate species.
authors.affiliation: Department of Medical Physiology, Texas A&M University Health Science Center, College Station 77843-1114, USA.
authors.forename: T V
authors.initials: TV
authors.lastname: Peterson
authors.forename: A B
authors.initials: AB
authors.lastname: Carter
authors.forename: R A
authors.initials: RA
authors.lastname: Miller
mesh_terms: D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D003404:Creatinine / Q000378:metabolism; D006339:Heart Rate / Q000187:drug effects; D007262:Infusions, Intravenous; D007668:Kidney / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D008252:Macaca fascicularis; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000008:administration & dosage / Q000494:pharmacology*; D009318:Natriuresis / Q000187:drug effects*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D010952:Plasma Substitutes; D010130:p-Aminohippuric Acid / Q000493:pharmacokinetics
chemical_list: D010952:Plasma Substitutes; D001120:Arginine; D003404:Creatinine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester; D010130:p-Aminohippuric Acid