Vanderpas J, Vertongen F
Blood. 1985 Dec;66(6):1272-7.
Erythrocytes of neonates and adults were incubated with increasing concentrations of H2O2 in the presence of a catalase inhibitor and in the absence of glucose; the pattern of oxidation of vitamin E was analyzed in relationship to that of glutathione, hemoglobin, and polyunsaturated fatty acids (PUFA), and in relationship to hemolysis. The changes of these various parameters were analyzed in function of H2O2 concentration and in relation to incubation time, and were compared in erythrocytes from neonates and adults. In the absence of H2O2, erythrocyte glutathione and tocopherol levels were similar in neonates and adults, despite fourfold lower serum vitamin E level in neonates; alpha-tocopherolquinone, methemoglobin, and malonyldialdehyde (MDA) were not detectable. At 0.375 mmol/L of H2O2, glutathione was completely oxidized. Erythrocyte alpha-tocopherol remained unchanged up to 0.75 mmol/L of H2O2, then decreased linearly, with increasing H2O2 concentrations to 10% of its initial value at 1.5 mmol/L of H2O2 in erythrocytes from neonates, whereas those from adults required 2.0 mmol/L of H2O2 (P less than .05) for the same level of oxidation. The formation of alpha-tocopherolquinone appeared inversely related to the decrease of alpha-tocopherol. The incubation time did not influence the level of vitamin E oxidation. MDA was generated autocatalytically and resulted in hemolysis at 1.5 mmol/L of H2O2 in erythrocytes from neonates and at 3.5 mmol/L of H2O2 in erythrocytes from adults (P less than .001). After four hours of incubation, MDA reached a plateau at a greater level (365 +/- 46 nmol/L) in cells of neonates than in those of adults (208 +/- 37 nmol/L/mL) (P less than .001). Hemoglobin was oxidized in the same pattern in erythrocytes of neonates and adults, and 90% of it was oxidized at 0.625 mmol/L of H2O2. In conclusion, in the experimental conditions used, oxidation of glutathione precedes that of vitamin E, and tocopherol is the last antioxidant to be consumed before the autocatalytic generation of MDA. Differences in the pattern of vitamin E oxidation, MDA generation, and hemolysis in erythrocytes from neonates and adults may be due to a lower erythrocyte vitamin E-PUFA ratio in neonates.
将新生儿和成年人的红细胞在过氧化氢酶抑制剂存在且无葡萄糖的情况下，与浓度不断增加的过氧化氢一起孵育；分析维生素E的氧化模式与谷胱甘肽、血红蛋白和多不饱和脂肪酸（PUFA）的氧化模式的关系，以及与溶血的关系。分析这些不同参数随过氧化氢浓度的变化及其与孵育时间的关系，并在新生儿和成年人的红细胞中进行比较。在无过氧化氢的情况下，尽管新生儿的血清维生素E水平低四倍，但新生儿和成年人红细胞中的谷胱甘肽和生育酚水平相似；未检测到α-生育酚醌、高铁血红蛋白和丙二醛（MDA）。在0.375 mmol/L的过氧化氢时，谷胱甘肽完全被氧化。在高达0.75 mmol/L的过氧化氢时，红细胞α-生育酚保持不变，然后随着过氧化氢浓度增加至1.5 mmol/L时线性下降，在新生儿红细胞中降至其初始值的10%，而成年人红细胞则需要2.0 mmol/L的过氧化氢（P<0.05）才能达到相同的氧化水平。α-生育酚醌的形成似乎与α-生育酚的减少呈负相关。孵育时间不影响维生素E的氧化水平。MDA在新生儿红细胞中1.5 mmol/L的过氧化氢时和成年人红细胞中3.5 mmol/L的过氧化氢时自动催化产生并导致溶血（P<0.001）。孵育4小时后，新生儿细胞中MDA达到的平台水平（365±46 nmol/L）高于成年人细胞（208±37 nmol/L/mL）（P<0.001）。新生儿和成年人红细胞中的血红蛋白以相同模式被氧化，在0.625 mmol/L的过氧化氢时90%被氧化。总之，在所使用的实验条件下，谷胱甘肽的氧化先于维生素E的氧化，并且生育酚是在MDA自动催化产生之前最后被消耗的抗氧化剂。新生儿和成年人红细胞中维生素E氧化模式、MDA产生和溶血的差异可能是由于新生儿红细胞中维生素E-PUFA比例较低。
