부산대학교 도서관

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 F(sub 2)-isoprostanes (8-iso-PGF(sub 2 alpha)) and PGF(sub 2 alpha)-metabolite (15-K-DH-PGF(sub 2 alpha), 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-(alpha)-tocopherol hydrogen succinate). Plasma (alpha)-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 (mu)mol/L, P < 0.001 and 181 +/- 6 vs. 275 +/- 27 (mu)mol/L trolox equivalents, P < 0.001). Urine 8-iso-PGF(sub 2 alpha) 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-PGF(sub 2 alpha) 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-PGF(sub 2 alpha) 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-PGF(sub 2 alpha) or 15-K-DH-PGF(sub 2 alpha) concentrations, liver total 8-iso-PGF(sub 2 alpha) 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-PGF(sub 2 alpha) but not total 8-iso-PGF(sub 2 alpha).