title: Simplified method for vitamin E determination in rat adipose tissue and mammary glands by high-performance liquid chromatography.
abstract: A method for vitamin E (alpha-tocopherol) measurement in rat adipose tissue and mammary gland has been developed and validated. Tissues were homogenized in ethanol-water (1:1) and extracted with n-hexane. Vitamin K1 was used as internal standard. Separation was performed by HPLC with methanol-water (96.5:3.5) as eluent in a Nucleosil C18 column (15 x 0.46 cm) at 40 degrees C. Detection was by fluorescence with excitation at 295 nm and emission at 350 nm for vitamin E and at 330 and 440 nm for vitamin K1. Standards and tissue extracts were checked for linearity giving correlation coefficients over 0.99 in a range of concentrations from 0.56 to 4.51 nmol/g in adipose tissue and from 2.18 to 17.4 nmol/g in mammary gland tissue. Intra-assay precision (R.S.D.) varied between 3 and 4%, whereas inter-assay precision was between 8 and 9%. Recoveries ranged between 95 +/- 3% and 98 +/- 11% for the two tissues, respectively. Vitamin E was measured in rats that had previously received one oral dose of this vitamin. Whereas vitamin E content in adipose tissue did not differ between late-pregnant and virgin rats, it was significantly higher in mammary gland of pregnant rats, and this difference could be related to the enhanced lipoprotein lipase activity in this group.
authors.affiliation: Facultad de CC Experimentales y Técnicas, Universidad S. Pablo-CEU, Urbanización Montepríncipe, Madrid, Spain.
authors.forename: F J
authors.initials: FJ
authors.lastname: Rupérez
authors.forename: C
authors.initials: C
authors.lastname: Barbas
authors.forename: M
authors.initials: M
authors.lastname: Castro
authors.forename: S
authors.initials: S
authors.lastname: Martínez
authors.forename: E
authors.initials: E
authors.lastname: Herrera
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005260:Female; D008321:Mammary Glands, Animal / Q000737:chemistry*; D011247:Pregnancy; D011786:Quality Control; D051381:Rats; D017208:Rats, Wistar; D012680:Sensitivity and Specificity; D014810:Vitamin E / Q000032:analysis*
chemical_list: D014810:Vitamin E