Résumé | The contributions from urate (58% - 18%), plasma proteins (21% - 10%), ascorbate (14% - 8%) and vitamin E (7% - 2%) to the Total Radical-trapping Antioxidant Parameter (TRAP) of plasma account for all of the peroxyl radical-trapping antioxidant activity in the majority of samples. Time dependent studies show that vitamin E is regenerated or spared during peroxyl radical attack by the water soluble antioxidants. The rates of uptake of dietary RRR- and SRR-[alpha]-tocopherols have been determined using deuterium labelled [alpha]-tocopherol acetates. There is a preferential uptake of the natural, RRR-[alpha]-tocopherol by all tissues (except the liver in the first month). These studies have potential implications for human nutrition. |
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