Silva E L, Moriel P, Chang Y H, Abdalla D S
Department of Clinical and Toxicological Analyses, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Brasil.
Biochem Mol Biol Int. 1995 Jul;36(3):679-87.
The activities of superoxide dismutase (SOD, EC 1.15.1.1), glutathione peroxidase (GPx, EC 1.11.1.9) and the levels of alpha-tocopherol and oxidized lipoproteins were investigated in the plasma of New Zealand rabbits either before or after cholesterol-diet induced hypercholesterolemia. Plasma SOD activity increased while GPx activity decreased after 60 days of cholesterol feeding. However, in the cholesterol-fed rabbits the release of superoxide dismutase fraction C from vasculature by heparin was lower than that in control rabbits. The levels of triglyceride hydroperoxides increased in low density and high density lipoproteins after feeding rabbits with the cholesterol-rich diet during 60 days. Also, a trend for increasing cholesteryl ester hydroperoxides was observed in beta-very low density and high density lipoproteins. An increase in alpha-tocopherol concentration (microM) was observed in very low density and low density lipoprotein fractions, but after normalization of these results to the cholesterol content of lipoprotein particles only the alpha-tocopherol content of low density lipoprotein remained higher after 60 days of cholesterol feeding. The data suggest that low glutathione peroxidase and superoxide dismutase fraction C activities may facilitate intravascular lipoprotein oxidation by oxidant species generated by the endothelium or blood cells.
在胆固醇饮食诱导的高胆固醇血症前后，对新西兰兔血浆中的超氧化物歧化酶（SOD，EC 1.15.1.1）、谷胱甘肽过氧化物酶（GPx，EC 1.11.1.9）活性以及α-生育酚和氧化脂蛋白水平进行了研究。喂食胆固醇60天后，血浆SOD活性增加而GPx活性降低。然而，在喂食胆固醇的兔子中，肝素从血管系统释放的超氧化物歧化酶C组分低于对照兔子。给兔子喂食富含胆固醇的饮食60天后，低密度和高密度脂蛋白中的甘油三酯氢过氧化物水平升高。此外，在β-极低密度和高密度脂蛋白中观察到胆固醇酯氢过氧化物有增加的趋势。在极低密度和低密度脂蛋白组分中观察到α-生育酚浓度（微摩尔）增加，但在将这些结果根据脂蛋白颗粒的胆固醇含量进行标准化后，仅在喂食胆固醇60天后低密度脂蛋白的α-生育酚含量仍然较高。数据表明，低谷胱甘肽过氧化物酶和超氧化物歧化酶C组分活性可能会促进由内皮细胞或血细胞产生的氧化剂对血管内脂蛋白的氧化作用。
