title: Redox dynamics of alpha-tocopherol in erythrocyte membranes of elderly patients with asymptomatic primary hyperlipidemia.
abstract: We investigated the redox dynamics of alpha-tocopherol in plasma and erythrocyte membranes in elderly patients with asymptomatic primary hyperlipidemia divided into three groups (hypercholesterolemia, hypertriglyceridemia and low high-density lipoprotein cholesterol levels) and in healthy elderly subjects to assess the antioxidative status of alpha-tocopherol. alpha-Tocopherol and alpha-tocopherolquinone were determined by high-performance liquid chromatography using a redox detection mode. In the erythrocyte membrane, there was no difference in the alpha-tocopherol concentration between hyperlipidemic and healthy subjects. The alpha-tocopherolquinone/alpha-tocopherol ratio in plasma and erythrocyte membrane, and the alpha-tocopherol in erythrocyte membrane/alpha-tocopherol in plasma ratio were significantly lower in elderly patients with hypercholesterolemia or hypertriglyceridemia. These findings suggest that the uptake ratio in erythrocyte membranes and the antioxidative activity of alpha-tocopherol in both plasma and erythrocyte membranes are decreased in elderly hyperlipidemic patients. These decreases may promote membrane lipid peroxidation or accelerate atherosclerosis.
authors.affiliation: Department of Geriatrics, Tokyo Medical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yanagawa
authors.forename: H
authors.initials: H
authors.lastname: Takeda
authors.forename: T
authors.initials: T
authors.lastname: Matsumiya
authors.forename: M
authors.initials: M
authors.lastname: Takasaki
mesh_terms: D000368:Aged; D000975:Antioxidants / Q000032:analysis / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000378:metabolism*; D005215:Fasting; D005260:Female; D005609:Free Radicals / Q000378:metabolism; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood* / Q000145:classification; D066298:In Vitro Techniques; D008297:Male; D010084:Oxidation-Reduction; D014810:Vitamin E / Q000031:analogs & derivatives / Q000032:analysis / Q000097:blood* / Q000737:chemistry
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D014810:Vitamin E; C002421:tocopherylquinone