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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, METHODS, RESULTS. Meshes: Adult, Antioxidants, Blood Coagulation, Creatinine, Factor VIII, Humans, Hypoxia, Isoprostanes, Oxidative Stress, Oxygen Consumption, Superoxide Dismutase, Thrombin, Vitamin E.
user
Does vitamin E suppress enhancement of factor VIII-dependent thrombin generation by systemic hypoxia? Context: Increased thrombin activity is an essential component of hemostatic reactions. This study elucidates how various hypoxic interventions impact endogenous thrombin generation (TG) after treatment with/without lipophilic antioxidant vitamin E. Twenty-four healthy sedentary men were randomly assigned to vitamin E (n=12) and placebo (n=12) groups. These subjects were randomly exposed to 12% (severe hypoxia), 15% (moderate hypoxia), 18% (light hypoxia), and 21% (normoxia) O(2) for 2 hours in a normobaric hypoxia chamber. A novel calibrated, automated thrombinography approach was used to measure TG in plasma. In the placebo group, severe hypoxia enhanced plasma FVIII level/activity and TG, which was accompanied by increased urinary 15-F2t-8-isoprostane level and decreased plasma total antioxidant content and superoxide dismutase activity. However, depletion of FVIII by incubation with anti-FVIII antibodies in plasma suppressed enhancement of TG by severe hypoxia. After administration of 1000 IU vitamin E, severe hypoxia did not significantly alter urinary 15-F(2t)-8-isoprostane level and plasma total antioxidant content, superoxide dismutase activity, FVIII level/activity, or TG. Moreover, redox status, FVIII level/activity, and TG were constant in response to moderate hypoxia, light hypoxia, and normoxia in the placebo and vitamin E groups.
assistant
We conclude that severe hypoxia promotes FVIII-dependent TG, likely by elevating oxidative stress; this hypoxic effect was ameliorated by pretreatment with vitamin E. Final Decision: yes