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S-nitrosoalbumin-mediated relaxation is enhanced by ascorbate and copper: Effects in pregnancy and preeclampsia plasma. Commentary

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  • Additional Information
    • Publication Information:
      Hagerstown, MD; Philadelphia, PA: Lippincott, 2005.
    • Publication Date:
      2005
    • Original Material:
      INIST-CNRS
    • Abstract:
      S-nitrosoalbumin (SNO-Alb) is a major reservoir of releasable nitric oxide (NO) in plasma. In preeclampsia, a pregnancy-specific disorder associated with endothelial dysfunction, we previously found significant elevations in plasma SNO-Alb concentrations and decreased plasma ascorbate (Asc) levels. This increased SNO-Alb may result from low-plasma Asc if Asc, along with transition metals (eg, copper [Cu]) are necessary for release of NO from S-nitrosothiols. We propose that vasodilator effects of SNO-Alb, mediated by release of NO, are fully realized only when Asc/Cu availability is sufficient. Relaxation responses to SNO-Alb or the control reduced human serum albumin (SH-Alb), and responses to pooled plasma from normal or preeclamptic pregnancies were examined in isolated mouse arteries. Arteries preconstricted with phenylephrine were exposed to SNO-Alb or SH-Alb at physiologically relevant concentrations. When free Cu was added in excess (10 μmol/L), NO release was not dependent on Asc. However, when Cu was added at lower (physiological) levels, NO release was dependent on Asc. The addition of Asc and Cu to SNO-Alb stimulated vasodilatory responses in isolated arteries >90%, whereas no change in the SH-Alb (5%) response was observed. Preeclampsia plasma with higher levels of SNO-Alb caused arteries to relax 44.1±4.7%, whereas normal pregnancy plasma caused 11.9±4.2% relaxation (P=0.007). These data indicate that SNO-Alb alone or in plasma can act as a potent vasodilator, and that sufficient Asc/Cu promotes this action. We suggest that the higher circulating levels of SNO-Alb, in women with preeclampsia, reflect a deficiency in Asc/Cu-mediated release of NO from SNO-Alb.
    • File Description:
      text
    • Author Affiliations:
      Magee-Womens Research Institute and Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, Pa, United States
      Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, Pa, United States
      Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC, United States
      Department of Medicine, Duke University Medical Center, Durham, NC, United States
      Department of Chemistry and Biochemistry, Montana State University, Bozeman, Mont., United States
      Department of Biochemistry, Duke University Medical Center, Durham, NC, United States
      Magee-Womens Research Institute and Department of Obstetrics, Gynecology, and Reproductive Sciences, University of Pittsburgh, Pittsburgh, Pa, United States
      Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, United States
    • ISSN:
      0194-911X
    • Rights:
      Copyright 2005 INIST-CNRS
      CC BY 4.0
      Sauf mention contraire ci-dessus, le contenu de cette notice bibliographique peut être utilisé dans le cadre d’une licence CC BY 4.0 Inist-CNRS / Unless otherwise stated above, the content of this bibliographic record may be used under a CC BY 4.0 licence by Inist-CNRS / A menos que se haya señalado antes, el contenido de este registro bibliográfico puede ser utilizado al amparo de una licencia CC BY 4.0 Inist-CNRS
    • Notes:
      Gynecology. Andrology. Obstetrics
    • Accession Number:
      edscal.16411356