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Artigo Acesso aberto Produção Nacional Revisado por pares
BIBTEX RIS

Ascorbic acid improves impaired venous and arterial endothelium-dependent dilation in smokers1

2005; Springer Nature; Volume: 26; Issue: 4 Linguagem: Inglês

10.1111/j.1745-7254.2005.00069.x

ISSN

1745-7254

Autores

Márcio Gonçalves de Sousa, Juan Carlos Yugar‐Toledo, Marcelo Custódio Rubira, Sílvia Elaine Ferreira‐Melo, Rodrigo Della Méa Plentz, D. Barbieri, Fernanda Marciano Consolim‐Colombo, Maria Cláudia Irigoyen, Heitor Moreno,

Tópico(s)

Antioxidant Activity and Oxidative Stress

Resumo

To compare the acute effects of ascorbic acid on vasodilation of veins and arteries in vivo.Twenty-six healthy non-smokers and 23 healthy moderate smokers were recruited in this study. The dorsal hand vein compliance technique and flow-mediated dilation were used. Dose-response curves to bradykinin and sodium nitroprusside were constructed to test the endothelium-dependent and -independent relaxation before and after acute infusion of ascorbic acid.Smokers had an impaired venodilation with bradykinin compared with non-smokers (68.3%+/-13.2% vs 93.7%+/-20.1%, respectively; P<0.05). Ascorbic acid administration in the dorsal hand vein significantly increased the venodilation with bradykinin in smokers (68.3%+/-13.2% vs 89.5%+/-6.3% before and after infusion, respectively; P<0.05) but not in non-smokers (93.7%+/-20.1% vs 86.4%+/-12.4% before and after infusion, respectively). Similarly, the arterial response in smokers had an impaired endothelium-dependent dilation compared with that in non-smokers (8.8%+/-2.7% vs 15.2%+/-2.3%, respectively; P<0.05) and ascorbic acid restored this response in smokers (8.8%+/-2.7% vs 18.7%+/-6.5% before and after infusion, respectively; P<0.05), but no difference was seen in non-smokers (15.2%+/-2.3% vs 14.0%+/-4.4% before and after infusion, respectively). The endothelium-independent dilation did not differ in both the groups studied. No important hemodynamic change was detected using the Portapress device.Smokers had impaired endothelium-dependent vasodilation responsiveness in both arterial and venous systems. Ascorbic acid restores this responsiveness in smokers.

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