PL EN


Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników
2007 | 58 | 2 |
Tytuł artykułu

Homocysteine induces endothelial dysfunction via inhibition of arginine transport

Treść / Zawartość
Warianty tytułu
Języki publikacji
EN
Abstrakty
EN
Hyperhomocysteinemia is an independent risk factor for cardiovascular diseases. High levels of plasma homocysteine (HCY) increase oxidative stress and reduce endothelial-dependent relaxation. We determined whether hyperhomocysteinemia-induced endothelial dysfunction is mediated through inhibition of cellular transport of L-arginine. In endothelial cells, HCY had a biphasic effect on arginine transport. HCY treatment for 6 hr increased L-arginine uptake by 34%; however, uptake was decreased by 25% after 24 h. HCY caused membrane hyperpolarization during both 6 and 24 h incubation periods, indicating that the negative charge facilitating arginine uptake was maintained. HCY significantly reduced expression of cellular arginine transporter protein (CAT-1) after 24 h treatment; whereas endothelial nitric oxide synthase (eNOS) protein levels and basal eNOS activity were not altered. Nevertheless, nitric oxide (NO) formation was significantly decreased. The antioxidant ascorbic acid prevented the effect of HCY on arginine transport. HCY induced formation of the peroxynitrite biomarker nitrotyrosine, which was blocked by supplemental L-arginine. HCY treatment of aortic rings caused decreased vasorelaxation to acetylcholine, which was prevented by supplemental arginine. In conclusion, HCY decreased NO formation and induced endothelial dysfunction without altering protein level or basal activity of eNOS, but through decreases in function and protein expression of the CAT-1 transporter. Reduced arginine supply may lead to eNOS uncoupling and generation of superoxide, contributing to HCY-induced oxidative stress.
Wydawca
-
Rocznik
Tom
58
Numer
2
Opis fizyczny
p.191-206,fig.,ref.
Twórcy
autor
  • Medical College of Georgia, Augusta, GA 30912 USA
Bibliografia
Typ dokumentu
Bibliografia
Identyfikatory
Identyfikator YADDA
bwmeta1.element.agro-article-859f6087-81c7-415e-b50f-dc63a19596aa
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.