• Title of article

    Ascorbyl radical formation in patients with sepsis: Effect of ascorbate loading

  • Author/Authors

    Helen F. Galley، نويسنده , , Michael J. Davies، نويسنده , , Nigel R. Webster، نويسنده ,

  • Issue Information
    روزنامه با شماره پیاپی سال 1996
  • Pages
    5
  • From page
    139
  • To page
    143
  • Abstract
    Patients with sepsis have low concentrations of antioxidants, including ascorbic acid, and also have increased concentrations of markers of free radical damage. Although ascorbic acid is a potent antioxidant, it can act as a prooxidant by promoting iron-catalysed reactions. We measured baseline total vitamin C and bleomycin-detectable “free” iron levels and ascorbyl radical concentrations before and after intravenous infusion of 1 g ascorbic acid in patients with sepsis and healthy control subjects. Vitamin C concentrations were decreased in patients compared to healthy subjects (p<0.0001), and “free” iron was increased (p < 0.002). Preinfusion ascorbyl radical concentrations were not different in patients and controls. Postinfusion ascorbyl radical levels increased in both controls and patients, with larger increases in healthy subjects (p < 0.0001), suggesting suboptimal basal vitamin C levels and increased scavenging of a constant oxidant pool by ascorbate in the controls. In the patients, who were all vitamin C deficient, infused ascorbate was rapidly consumed, either via the promotion of redox cycling of iron or as a result of radical scavenging. This study demonstrates markedly different handling of infused ascorbate in patients with sepsis and healthy subjects, and further studies are needed to elucidate the relative anti- and pro-antioxidant mechanisms of ascorbate in patients with raised “free” iron levels.
  • Keywords
    ascorbic acid , Electron paramagnetic resonance spectroscopy , Iron , vitamin C , free radicals , Septicemia , Spin traps
  • Journal title
    Free Radical Biology and Medicine
  • Serial Year
    1996
  • Journal title
    Free Radical Biology and Medicine
  • Record number

    517246