title: Simultaneous determination of alpha-, gamma-tocopherol and their quinones in rats plasma and tissues using reversed-phase high-performance liquid chromatography.
abstract: We established a method to determine simultaneously alpha- and gamma-tocopherol (-Toc) and their quinones (alpha-TQ and p-gamma-TQ) in biological samples by reverse-phase high-performance liquid chromatography (HPLC). Tocs had a shorter retention time than TQs, and alpha-forms had a shorter retention times than gamma-forms. Four peaks of Tocs and TQs were completely separated by this method. Subsequently, we investigated the distribution of alpha-, gamma-Toc and TQ in rat tissues and the excretion of Tocs and TQs in rat bile by the above HPLC method. Rats deficient in vitamin E were divided into two groups, gamma-Toc group and alpha+ gamma-Toc group, and tissues were collected at 6 and 24 h after intravenous administration of Tocs. Also, bile collection was started immediately and performed at 3 h intervals during 24 h after intravenous administration. The concentration of alpha- and gamma-Toc and their quinones in plasma, tissues and bile were determined by this method. Gamma-Toc concentration in the liver of alpha+gamma-Toc group was higher than that of gamma-Toc group. However, p-gamma-TQ in the liver was not significantly different between alpha+gamma-Toc group and gamma-Toc group. Also, both alpha-TQ and p-gamma-TQ were present in very low concentrations in all tissues. Therefore, we suggested that the distribution of gamma-Toc is affected by alpha-Toc present in vivo, but the oxidative production of p-gamma-TQ from gamma-Toc is not affected.
authors.affiliation: Institute of Environmental Science for Human Life, Ochanomizu University, Tokyo, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Kiyose
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: T
authors.initials: T
authors.lastname: Ueda
authors.forename: O
authors.initials: O
authors.lastname: Igarashi
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000032:analysis*; D001646:Bile / Q000378:metabolism; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D007275:Injections, Intravenous; D008297:Male; D011809:Quinones / Q000032:analysis / Q000097:blood*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D013997:Time Factors; D014018:Tissue Distribution; D014811:Vitamin E Deficiency / Q000097:blood*; D024502:alpha-Tocopherol / Q000032:analysis / Q000097:blood*; D024504:gamma-Tocopherol / Q000032:analysis / Q000097:blood*
chemical_list: D000975:Antioxidants; D011809:Quinones; D024504:gamma-Tocopherol; D024502:alpha-Tocopherol