This thesis presents experimental research findings into the effects of exercise-induced free oxidative stress. Study 1 - Study one tested the hypothesis that acute high intensity exercise produces free radicals which may cause subsequent damage to DNA, lipids and proteins. It is proposed that the observed DNA damage is the result of the extraction of hydrogen ions from polyunsaturated fatty acids in lipid membranes by a primary free radical species. This reaction initiates the process of lipid peroxidation leading to increased cellular and nuclear membrane permeability exposing DNA to oxidative attack by primary or secondary free radical species. Study 2 - Study two tested the efficacy of chronic watercress supplementation (85g daily for eight weeks) against oxidative stress. Exhaustive exercise demonstrated an increased propensity for oxidative stress (DNA damage and lipid peroxidation) which is potentially mediated by the reactive oxygen species hydrogen peroxide. Chronic supplementation with watercress evoked positive changes in lipid soluble antioxidants which contributed to a reduction in hydrogen peroxide and promoted protection to indices of oxidative stress. Study 3 - The effects of dietary intervention with an acute dose of watercress (85 g 2 hours prior to exercise) on oxidative stress was investigated. Results indicate that watercress acts as potent antioxidant increasing plasma lipid soluble antioxidants. This additional antioxidant protection prevented exercise-induced DNA damage, and decreased lipid peroxidation. Study 4 - The effect of high intensity exercise (100 concentric muscle contractions) and 14 days supplementation with α-lipoic acid on mitochondrial DNA and peripheral indices of oxidative stress were examined. Exercise caused a significant increase in mitochondrial 8-OHdG concentration in both supplemented and non-supplement groups as total antioxidant status decreased. Total antioxidant status of plasma significantly increased in the supplemented group and provided increased antioxidant prophylaxis. Protein oxidation increased with exercise under both supplemented and non-supplemented conditions.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:602700 |
| Date | January 2013 |
| Creators | Fogarty, Mark Christopher |
| Publisher | Ulster University |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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