title: Role of renal nerves in natriuresis of L-NMMA infusion in SHR and WKY rats.
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 NG-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 approximately 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 micrograms.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 (FENa) 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 (FEPi; 18.18 +/- 5.33 and 6.34 +/- 2.29%, respectively), suggesting a reduction in proximal tubule reabsorption. In the SHRs with acute renal denervation, FENa was significantly increased by L-NMMA; however, FENa was significantly reduced (2.03 +/- 0.70%; P < 0.05) in comparison with innervated SHRs and was associated with no increase in FEPi (FEPi = -0.72 +/- 1.23%).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Physiology and Biophysics, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Khraibi
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D003714:Denervation; D006973:Hypertension / Q000503:physiopathology*; D007668:Kidney / Q000294:innervation*; D008297:Male; D009318:Natriuresis / Q000187:drug effects* / Q000502:physiology*; D009392:Nephrectomy; D009420:Nervous System / Q000503:physiopathology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D010710:Phosphates / Q000652:urine; D051381:Rats; D011918:Rats, Inbred SHR / Q000502:physiology*; D011921:Rats, Inbred WKY / Q000502:physiology; D019323:omega-N-Methylarginine
chemical_list: D010710:Phosphates; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D001120:Arginine