Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension
Braz. j. med. biol. res
;
35(11): 1301-1309, Nov. 2002. tab, graf
Artículo
en Inglés
| LILACS
| ID: lil-326262
ABSTRACT
The objective of the present study was to identify disturbances of nitric oxide radical (ANO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations ofANO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 ± 9.7 years; blood pressure, 148.3 ± 24.8/90.8 ± 10.2 mmHg) and in 11 healthy subjects (N: 48.4 ± 7.0 years; blood pressure, 119.4 ± 9.4/75.0 ± 8.0 mmHg).Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1 percent increase of diameter 90 s after hyperemia), and lower levels of ascorbate (H: 29.2 ± 26.0, N: 54.2 ± 24.9 æM), urate (H: 108.5 ± 18.9, N: 156.4 ± 26.3 æM), ß-carotene (H: 1.1 ± 0.8, N: 2.5 ± 1.2 nmol/mg cholesterol), and lycopene (H: 0.4 ± 0.2, N: 0.7 ± 0.2 nmol/mg cholesterol), in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3ß,5,6ß-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 ± 0.2, N: 0.7 ± 0.1 ng/ml) in plasma were increased in hypertensive patients. No differences were found for ANO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although ANO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides
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LILACS (Américas)
Asunto principal:
Endotelio Vascular
/
Peroxidación de Lípido
/
Estrés Oxidativo
/
Hipertensión
/
Óxido Nítrico
Tipo de estudio:
Estudio observacional
/
Factores de riesgo
Límite:
Adulto
/
Femenino
/
Humanos
/
Masculino
Idioma:
Inglés
Revista:
Braz. j. med. biol. res
Asunto de la revista:
Biologia
/
Medicina
Año:
2002
Tipo del documento:
Artículo
/
Documento de proyecto
País de afiliación:
Brasil
/
Estados Unidos
/
Uruguay
Institución/País de afiliación:
Universidad de la Republica/UY
/
Universidade Federal de Säo Paulo/BR
/
Universidade de Säo Paulo/BR
/
University of Southern California/US
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