Targeted and persistent effects of NO mediated by S-nitrosation of tissue thiols in arteries with endothelial dysfunction

Nitric Oxide. 2007 Aug;17(1):1-9. doi: 10.1016/j.niox.2007.04.003. Epub 2007 Apr 25.

Abstract

We have previously demonstrated that in endothelium-denuded arteries, S-nitrosation of cysteine residues is a mechanism of formation of releasable nitric oxide (NO) stores, accounting for the long-lasting relaxation induced by S-nitrosating agents like S-nitrosoglutathione (GSNO). Here, we have investigated whether such effects could also be obtained in arteries exhibiting oxidative stress-associated endothelial dysfunction. Rats were implanted or not with a minipump delivering saline or angiotensin II for 14 days. As expected, aorta from angiotensin II-infused rats exhibited increased level of superoxide anions (as evaluated with dihydroethidine as fluorescent probe) and a reduced relaxation to acetylcholine in comparison to saline group. Unlike aortic rings with endothelium from controls, those from angiotensin II-infused rats exhibited persistent hyporesponsiveness to phenylephrine after pre-exposure to GSNO, as well as relaxation upon addition of N-acetylcysteine (NAC, which can displace NO from cysteine-NO residues) or HgCl(2) (which cleaves S-NO bonds). In aorta from angiotensin II-infused rats, GSNO also induced a persistent increase in cysteine-NO residues (as determined using anti-cysteine-NO antiserum), which was blunted by NAC and HgCl(2). These data indicate that (i) the vasorelaxant influence of releasable NO stores is unmasked by endothelial dysfunction (ii) S-nitrosation of cysteine residues remains an effective mechanism of formation of releasable NO stores in arteries exhibited oxidative stress-associated endothelial dysfunction. Thus, formation of releasable NO stores by S-nitrosating agents allows targeted vasculoprotective effects of NO at sites of endothelial dysfunction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiotensin II / metabolism
  • Animals
  • Anions
  • Cysteine / chemistry
  • Cysteine / metabolism
  • Endothelium, Vascular / metabolism*
  • Endothelium, Vascular / pathology
  • Male
  • Models, Biological
  • NG-Nitroarginine Methyl Ester / metabolism
  • Nitric Oxide / metabolism*
  • Nitrogen / chemistry*
  • Oxidative Stress
  • Rats
  • Rats, Wistar
  • Reactive Oxygen Species
  • Sulfhydryl Compounds / chemistry*

Substances

  • Anions
  • Reactive Oxygen Species
  • Sulfhydryl Compounds
  • Angiotensin II
  • Nitric Oxide
  • Cysteine
  • Nitrogen
  • NG-Nitroarginine Methyl Ester