Endothelin-1 increases superoxide production in human coronary artery bypass grafts.
Life Sci
; 91(13-14): 723-8, 2012 Oct 15.
Article
em En
| MEDLINE
| ID: mdl-22483692
ABSTRACT
AIMS:
Endothelin-1 (ET-1) has been shown to increase endothelial superoxide (O(2)(-)) production in experimental animal models. It is unclear whether ET-1 increases O(2)(-) production in humans. We sought to elucidate whether ET-1 increases O(2)(-) production in human vessels and to identify the mechanism behind this effect. MAINMETHODS:
Segments of internal mammary artery (IMA) and human saphenous vein (HSV) were harvested from 90 patients undergoing elective coronary artery bypass graft surgery. Paired vessel rings were incubated in the presence and absence of ET-1 (10(-10)M), the ET(A) receptor antagonist BQ123 alone, or in combination with the ET(B) receptor antagonist BQ788 (dual BQ) and known inhibitors of sources of O(2)(-) and further analysed for O(2)(-) production using lucigenin-enhanced chemiluminescence and DHE fluorescence. KEYFINDINGS:
ET-1 increased O(2)(-) production in both IMA (2.6 ± 1.5 vs. 1.4 ± 0.8 relative light units/s/mg tissue (RLU); n=33; p < 0.0001) and HSV (1.4 ± 0.8 vs. 1.1 ± 0.6 RLU; n=24; p<0.05). The increase in O(2)(-)production induced by ET-1 in IMA was inhibited by co-incubation with dual BQ (p < 0.05; n=15) and BQ123 (p<0.05; n = 17). Of known O(2)(-) inhibitors, only incubation with Tiron and diphenyleneiodonium resulted in a significant reduction in ET-mediated O(2)(-) production.SIGNIFICANCE:
ET-1 increases O(2)(-) production especially in human arteries and less so in veins from patients with coronary artery disease via a receptor-dependent pathway involving a flavin dependent enzyme which is likely to be NADPH oxidase. Production of O(2)(-) may be an important factor underlying the negative effects of ET-1 on vascular function such as impairment of endothelium-dependent vasodilatation and pro-inflammatory effects.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doença da Artéria Coronariana
/
Ponte de Artéria Coronária
/
Superóxidos
/
Endotelina-1
Tipo de estudo:
Prognostic_studies
Limite:
Aged
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Life Sci
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Suécia