Effects of renal perfusion pressure on renal interstitial hydrostatic pressure and Na+ excretion: role of endothelium-derived nitric oxide.
Nephron
; 78(1): 104-11, 1998.
Article
em En
| MEDLINE
| ID: mdl-9453411
ABSTRACT
The purpose of this study was to examine the role of endothelium-derived nitric oxide in modulating the effect of renal perfusion pressure (RPP) on renal interstitial hydrostatic pressure (RIHP) and urinary Na+ excretion (UNaV). The effects of RPP on renal hemodynamics, RIHP, and Na+ and Li+ excretions were determined in control Sprague-Dawley rats, in Sprague-Dawley rats pretreated with intravenous infusion of NG-nitro-L-arginine methyl ester (L-NAME) at doses of 1, 5, and 50 microg/kg/min, and in rats pretreated with L-NAME (5 microg/kg/min) plus L-arginine (10 mg/kg/min). The RPP was changed from 95 to 135 mm Hg by an electronically servo-controlled aortic occluder above the renal arteries in all groups. Increasing RPP in control rats from 95 to 135 mm Hg increased RIHP (from 4.4 +/- 0.5 to 8.7 +/- 1.2 mm Hg), UNaV (from 2.37 +/- 0.61 to 8.29 +/- 1.59 microEq/min), and fractional excretion of Li+ (from 38.0 +/- 2.5 to 51.4 +/- 6.0%). In rats pretreated with L-NAME (5 microg/kg/min), increases in RPP from 95 to 135 mm Hg had no effect on RIHP (from 1.6 +/- 0.4 to 2.2 +/- 0.6 mm Hg) or fractional excretion of Li+ and markedly attenuated pressure-natriuresis relationship (from 1.84 +/- 0.50 to 2.88 +/- 0.65 microEq/min). Although L-NAME did reduce renal plasma flow and glomerular filtration rate, the autoregulatory responses to RPP were maintained. In rats pretreated with L-NAME plus L-arginine, RIHP, UNaV, and fractional excretion of Li+ responses to RPP were similar to the control rats. The results of this study indicate that endothelium-derived nitric oxide plays an important role in modulating the effect of RPP on Na+ excretion by enhancing the transmission of RPP into the renal interstitium.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Circulação Renal
/
Sódio
/
Pressão Sanguínea
/
Pressão Hidrostática
/
Rim
/
Óxido Nítrico
Limite:
Animals
Idioma:
En
Revista:
Nephron
Ano de publicação:
1998
Tipo de documento:
Article