Biokinetics of dietary RRR-alpha-tocopherol in the male guinea pig at three dietary levels of vitamin C and two levels of vitamin E. Evidence that vitamin C does not spare vitamin E in vivo
- National Research Council of Canada, Ottawa, Ontario (Canada)
The net rates of uptake of new and loss of old 2R,4'R,8'R-alpha-tocopherol (RRR-alpha-TOH) have been measured in the blood and in nine tissues of male guinea pigs over an eight week period by feeding diets containing deuterium-labelled alpha-tocopheryl acetate (d6-RRR-alpha-TOAc). There was an initial two week lead-in period during which 24 animals (the high vitamin E (HE) group) received diets containing 36 mg of unlabelled (d0) RRR-alpha-TOAc and 250 mg of ascorbic acid per kg diet, while another 24 animals (the low vitamin E (LE) group) received diets containing 5 mg d0-RRR-alpha-TOAc and 250 mg ascorbic acid per kg diet. The HE group was then divided into three equal subgroups, which were fed diets containing 36 mg d6-RRR-alpha-TOAc and 5000 mg (the high vitamin C (HEHC) subgroup), 250 mg (the normal vitamin C (HENC) subgroup) and 50 mg (the low vitamin C (HELC) subgroup) ascorbic acid per kg diet. One animal from each group was sacrificed each week and the blood and tissues were analyzed for d0- and d6-RRR-alpha-TOH by gas chromatography-mass spectrometry. The LE group was similarly divided into three equal subgroups with animals receiving diets containing 5 mg d6-RRR-alpha-TOAc and 5,000 mg (LEHC), 250 mg (LENC) and 50 mg (LELC) ascorbic acid per kg diet with a similar protocol being followed for sacrifice and analyses. In the HE group the total (d0(-) + d6-) RRR-alpha-TOH concentrations in blood and tissues remained essentially constant over the eight week experiment, whereas in the LE group the total RRR-alpha-TOH concentrations declined noticeably. There were no significant differences in the concentrations of old d0-RRR-alpha-TOH nor in the concentrations of new d6-RRR-alpha-TOH found in any tissue at a particular time between the HEHC, HENC and HELC subgroups, nor between the LEHC, LENC and LELC subgroups.
- OSTI ID:
- 7064129
- Journal Information:
- Lipids; (USA), Vol. 25:4; ISSN 0024-4201
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ASCORBIC ACID
BIOCHEMICAL REACTION KINETICS
VITAMIN E
TISSUE DISTRIBUTION
DEUTERIUM
DIET
GAS CHROMATOGRAPHY
GUINEA PIGS
MASS SPECTROSCOPY
MEMBRANE TRANSPORT
RATS
TRACER TECHNIQUES
ANIMALS
CHROMATOGRAPHY
DISTRIBUTION
HYDROGEN ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAMMALS
NUCLEI
ODD-ODD NUCLEI
REACTION KINETICS
RODENTS
SEPARATION PROCESSES
SPECTROSCOPY
STABLE ISOTOPES
VERTEBRATES
VITAMINS
550201* - Biochemistry- Tracer Techniques