Role of cyclooxygenase-2 in the prolonged regulation of renal function.
Hypertension
; 40(5): 721-8, 2002 Nov.
Article
em En
| MEDLINE
| ID: mdl-12411468
ABSTRACT
The role of cyclooxygenase-2 (COX-2) in the prolonged regulation of renal function was evaluated during changes in sodium intake and reduction of NO synthesis. It was evaluated in conscious dogs by administering a selective inhibitor (nimesulide) during 8 consecutive days. Nimesulide administration to dogs with normal or high sodium load did not modify glomerular filtration rate but reduced renal blood flow (16%; P<0.05). The vasoconstriction elicited by COX-2 inhibition was greater when NO production was inhibited because glomerular filtration rate decreased by >25% when nimesulide was administered to dogs with a reduced NO synthesis. During low sodium intake, COX-2 inhibition elicited a decrease (P<0.05) of both glomerular filtration rate (34%) and renal blood flow (31%). Sodium excretion only decreased (P<0.05) during the first day of COX-2 inhibition in dogs with normal or high sodium load. The increase in plasma potassium levels elicited by COX-2 inhibition was greater in dogs with low sodium intake and was enhanced when NO production was inhibited. This change in potassium was not secondary to a decrease in plasma aldosterone levels. The results of this study suggest that COX-2-derived metabolites (1) play a more important role in the long-term regulation of renal hemodynamic when sodium intake is low, (2) protect the renal vasculature from the vasoconstriction secondary to a reduction in NO, (3) are only acutely involved in regulating urinary sodium excretion, and (4) play a more important role in regulating plasma potassium concentration when NO synthesis is reduced.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prostaglandina-Endoperóxido Sintases
/
Isoenzimas
/
Rim
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Hypertension
Ano de publicação:
2002
Tipo de documento:
Article