Biochemical interaction of arachidonic acid and vitamin E in human platelets.
The effect of alpha-tocopherol on the oxidative transformation of arachidonic acid was investigated in human platelets. The major products of lipoxygenase and cyclo-oxygenase pathways were separated by high performance liquid chromatography (HPLC) and thin layer chromatography (TLC) evaluated by scanning the radiochromatograms. This study differs from others in the vitamin E field in important aspects of its experimental design: the prelabeling of platelets with non-aggregating concentrations of 14C-arachidonic acid, and the addition of alpha-tocopherol as a colloidal suspension rather than as an ethanolic solution. A moderately potent but consistent reduction of apparent cyclo-oxygenase activity by alpha-tocopherol could be demonstrated by TLC and HPLC. This effect was best shown by the change of the HETE/HHT ratio which increased significantly in vitamin E-treated platelets. It was found to be dose-dependent up to 1 microM alpha-tocopherol, the maximal concentration tested in this study. Alpha-tocopherol quinone was equally effective in this action.
D001091:Arachidonate Lipoxygenases; D001095:Arachidonic Acids / Q000378:metabolism / Q000494:pharmacology*; D001792:Blood Platelets / Q000187:drug effects* / Q000201:enzymology; D016861:Cyclooxygenase Inhibitors; D006801:Humans; D008084:Lipoxygenase / Q000378:metabolism; D010084:Oxidation-Reduction; D010974:Platelet Aggregation / Q000187:drug effects*; D014810:Vitamin E / Q000031:analogs & derivatives / Q000494:pharmacology*
D001095:Arachidonic Acids; D016861:Cyclooxygenase Inhibitors; D014810:Vitamin E; C002421:tocopherylquinone; D001091:Arachidonate Lipoxygenases; D008084:Lipoxygenase