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in Rats1
* Clinical Nutrition Research, Department of Public Health and Caring Sciences/Geriatrics, and ** Department of Medical Cell Biology, Faculty of Medicine, Uppsala University, Sweden
2To whom correspondence should be addressed.
Lipid peroxidation is thought to be an important factor in the
pathophysiology of a number of diseases and in the process of aging. We
investigated the effects of supplementation with vitamin E on lipid
peroxidation in rats. Both free radical-induced nonenzymatic- and
cyclooxygenase-catalyzed enzymatic lipid peroxidation were
investigated by measuring the levels of F2-isoprostanes
(8-iso-PGF2
) and PGF2
-metabolite
(15-K-DH-PGF2
), respectively, in blood, urine and liver.
Samples were collected from control rats (n = 6)
and from rats supplemented with vitamin E in the diet for 3 wk
(n = 8, 20 g/kg diet of DL-
-tocopherol hydrogen succinate). Plasma
-tocopherol concentration and antioxidative capacity were greater in
the vitamin E-supplemented rats than in the control rats (17.9
± 1.7 vs. 50.4 ± 10.4 µmol/L, P < 0.001 and 181 ± 6 vs. 275 ± 27 µmol/L trolox equivalents, P < 0.001). Urine 8-iso-PGF2
tended
to be lower in the vitamin E-supplemented rats (0.72 ± 0.40
vs. 0.34 ± 0.19 nmol/mmol creatinine, P = 0.056). Urine 15-K-DH-PGF2
was lower due to vitamin E supplementation (0.97 ± 0.38 vs. 0.56 ± 0.21 nmol/mmol
creatinine, P < 0.05), as was liver-free
8-iso-PGF2
concentration (0.47 ± 0.11 vs. 0.18
± 0.04 nmol/g, P < 0.001). Supplementation
with vitamin E did not affect plasma 8-iso-PGF2
or 15-K-DH-PGF2
concentrations, liver total 8-iso-PGF2
or plasma malondialdehyde levels. Thus,
vitamin E supplementation reduced urine basal levels of biomarkers of
both nonenzymatic and enzymatic lipid peroxidation. In liver, vitamin E
reduced the basal level of free 8-iso-PGF2
but not total 8-iso-PGF2
.
KEY WORDS: vitamin E lipid peroxidation F2-isoprostane prostaglandin rats