Role of renal nerves in natriuresis of L-NMMA infusion in SHR and WKY rats

Research output: Contribution to journalArticlepeer-review

18 Scopus citations

Abstract

The purpose of this study was to determine the role of the renal nerves in the natriuresis and diuresis that is observed with the systemic infusion of a high dose of N(G)-monomethyl-L-arginine (L-NMMA) to inhibit nitric oxide synthesis in the Okamoto spontaneously hypertensive rat (SHR) and the Wistar- Kyoto (WKY) rat. All rats in this study underwent a unilateral nephrectomy ~2 wk prior to the acute experiment. On the day of the acute experiment, renal denervation of the remaining left kidney was performed in one group of SHR (n = 6) and one group of WKY rats (n = 9). Another group of SHR (n = 6) and WKY rats (n = 10) had an innervated kidney. A control clearance period was taken, and then an L-NMMA (15 mg/kg bolus followed by 500 μg · kg-1 · min-1 continuous infusion) infusion period followed in all four groups of rats. In the innervated SHR and WKY rats, the increases in fractional excretion of sodium (FE(Na)) were 5.11 ± 0.70 and 3.58 ± 0.38%, respectively, with the infusion of L-NMMA and were associated with significant increases in fractional excretions of phosphate (FE(P(i)); 18.18 ± 5.33 and 6.34 ± 2.29%, respectively), suggesting a reduction in proximal tubule reabsorption. In the SHRs with acute renal denervation, FE(Na) was significantly increased by L-NMMA; however, FE(Na) was significantly reduced (2.03 ± 0.70%; P < 0.05) in comparison with innervated SHRs and was associated with no increase in FE(P(i)) (FE(P(i)) = -0.72 ± 1.23%). In contrast, the natriuretic [FE(Na) = 2.88 ± 0.75%; not significant (NS)] and phosphaturic (FE(P(i)) = 5.04 ± 3.40%; NS) responses to L-NMMA infusion were similar in WKY rats with acute renal denervation in comparison with innervated WKY rats. These results suggest that in the SHR the inhibition of reabsorption by the proximal tubule with L-NMMA infusion requires the presence of the renal nerves and that the natriuretic and diuretic responses to nitric oxide synthesis inhibition are partially dependent on renal innervation.

Original languageBritish English
Pages (from-to)F17-F21
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume269
Issue number1 38-1
DOIs
StatePublished - 1995

Keywords

  • N(G)-monomethyl-L-arginine infusion
  • nitric oxide inhibition
  • proximal tubule reabsorption
  • renal denervation
  • spontaneously hypertensive rat
  • Wistar-Kyoto rat

Fingerprint

Dive into the research topics of 'Role of renal nerves in natriuresis of L-NMMA infusion in SHR and WKY rats'. Together they form a unique fingerprint.

Cite this