title: Age-related changes in alpha-tocopherol dynamics with relation to lipid hydroperoxide content and fluidity of rat erythrocyte membrane.
abstract: Age-related changes in alpha-tocopherol dynamics in plasma and erythrocyte membranes of 10- to 120-week-old rats were investigated by high-performance liquid chromatography (HPLC) with redox detection mode. Furthermore, changes in lipid hydroperoxide content and fluidity of erythrocyte membrane with age were assessed using chemiluminescence-HPLC and Fourier transform infrared spectrophotometer, respectively. A slight increase in the alpha-tocopherolquinone/alpha-tocopherol ratio in erythrocyte membrane and a decrease in the alpha-tocopherol in erythrocyte membrane/alpha-tocopherol in plasma ratio were observed. A significant increase in lipid hydroperoxide content and a marked decrease in the fluidity of erythrocyte membrane were seen with age. These findings suggest that alpha-tocopherol uptake in erythrocyte membrane declines, and utilization rate of alpha-tocopherol in erythrocyte membrane increases age-dependently. These changes, which enhanced lipid peroxidation and consequently reduced membrane fluidity, may be caused by the impairment of this transfer mechanism.
authors.affiliation: Department of Pharmacology, 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: Egashira
authors.forename: K
authors.initials: K
authors.lastname: Sakai
authors.forename: M
authors.initials: M
authors.lastname: Takasaki
authors.forename: T
authors.initials: T
authors.lastname: Matsumiya
mesh_terms: D000375:Aging / Q000097:blood*; D000818:Animals; D004910:Erythrocyte Membrane / Q000378:metabolism*; D008054:Lipid Peroxides / Q000097:blood*; D008297:Male; D008560:Membrane Fluidity; D010713:Phosphatidylcholines / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D014810:Vitamin E / Q000031:analogs & derivatives / Q000097:blood*
chemical_list: D008054:Lipid Peroxides; D010713:Phosphatidylcholines; C057590:phosphatidylcholine hydroperoxide; D014810:Vitamin E; C002421:tocopherylquinone