Decrease in platelet reduced glutathione increases lipoxygenase activity and decreases vitamin E.
Unstimulated normal human blood platelets were treated with azodicarboxylic acid bis(dimethylamide) (diamide), a thiol-oxidizing agent. Oxygenated arachidonic acid (AA) metabolites, malondialdehyde (MDA), and tocopherols were then quantified by high-performance liquid chromatography (HPLC). Diamide treatment partially decreased the amount of reduced glutathione (GSH) content and induced a subsequent decrease in peroxidase activity. However, formation of 12-hydroxy-eicosatetraenoic acid (12-HETE), the end-product of lipoxygenation of AA, increased. Formation of MDA, a marker of overall lipid peroxidation, was also enhanced. Furthermore, platelet alpha-tocopherol, but not gamma-tocopherol, significantly decreased. These results indicate that enhanced "basal" lipoxygenase activity, as a marker of specific AA oxygenation, may be linked to decreased platelet antioxidant status.
Calzada
C
C
Institut National de la Santé et de la Recherche Médicale U.205, Chimie Biologique INSA, Villeurbanne, France.
Véricel
E
E
Lagarde
M
M
D000975:Antioxidants; D001792:Blood Platelets / Q000378:metabolism*; D003958:Diamide; D005978:Glutathione / Q000378:metabolism*; D006801:Humans; D015227:Lipid Peroxidation; D008084:Lipoxygenase / Q000378:metabolism*; D010084:Oxidation-Reduction; D014810:Vitamin E / Q000378:metabolism*
D000975:Antioxidants; D003958:Diamide; D014810:Vitamin E; D008084:Lipoxygenase; D005978:Glutathione