ESTROGEN AND VITAMIN E EFFECTS ON LIPOPROTEIN OXIDATION IN POSTMENOPAUSAL WOMEN

我们以前已经证明，长期服用17 β-雌二醇 或维生素E对人类的显著抑制氧化， 密度脂蛋白（LDL）。 据报道雌激素可以再生 α-生育酚（维生素E）在氧化成α- 生育酚自由基，从而恢复其抗氧化潜力。 为了 评估雌二醇和维生素E联合给药是否可能 对LDL氧化的保护作用比单独使用更大，我们测量到 14名绝经后妇女LDL的氧化能力，通过 共轭二烯生成的分光光度测量 用CuCl2过氧化。 这些研究在基线时进行， 维生素E单药治疗6周（800 IU/天）或 经皮雌二醇（0.1 mg/天），和联合给药后， 维生素E和雌二醇（联合治疗）。 我们找到了 胆固醇和LDL浓度在单药治疗中没有改变， 与基线相比的联合治疗。 维生素E单药治疗或 雌二醇同样延长了LDL氧化的滞后时间。 维生素E和雌二醇联合治疗可延长LDL的滞后时间 氧化至与单独给予的任一种试剂相似的程度。 因此 单药治疗和联合治疗在以下方面无差异： 对LDL氧化的影响。 最后，减少 雌二醇和维生素E对LDL的氧化能力相似， 联合给药后观察到协同作用。 因此，在本发明中， 对绝经后妇女同时给予雌激素和维生素E可 对动脉粥样硬化及其后遗症的影响并不比 一个人

We have previously shown that chronic administration of 17beta-estradiol or vitamin E to humans significantly inhibits oxidation of their low density lipoprotein (LDL). Estrogen has been reported to regenerate alpha-tocopherol (vitamin E) following its oxidation to the alpha- tocopheryl radical, thus restoring its antioxidant potential. In order to assess whether coadministration of estradiol and vitamin E might have greater protective effect on LDL oxidation than either alone, we measured oxidizability of LDL from 14 postmenopausal women, assayed by spectrophotometric measurement of conjugated diene generation following peroxidation with CuCl2. The studies were performed at baseline, after monotherapy with 6 weeks of vitamin E (800 IU/day) or 3 weeks of transdermal estradiol (0.1 mg/day), and after combined administration of vitamin E and estradiol (combined therapy). We found the total cholesterol and LDL concentrations were not changed by monotherapy or combined therapy compared to baseline. Monotherapy with vitamin E or with estradiol similarly prolonged the lag time of LDL oxidation. Combined therapy with vitamin E and estradiol prolonged lag time of LDL oxidation to a similar extent as either agent given alone. Thus, there was no difference between monotherapy and combined therapy with regard to the effect on LDL oxidation. In conclusion, the reduction in oxidizability of LDL is similar between estradiol and vitamin E, with no synergism noted following combined administration. Thus, coadministration of estrogen and vitamin E to postmenopausal women may have no greater effect on atherosclerosis and its sequelae than either alone.