Brownlee N R, Huttner J J, Panganamala R V, Cornwell D G
J Lipid Res. 1977 Sep;18(5):635-44.
Red blood cells (RBC) from normal and vitamin E-deficient rats were incubated in a hypertonic solution of reduced glutathione adjusted to pH 8. Methemoglobin formation occurred in intact RBC from both normal and vitamin E-deficient rats. Hemolysis was significantly greater in RBC from vitamin E-deficient rats. Experiments with catalase, superoxide dismutase, and methional showed that H(2)O(2) was the primary extracellular source of oxidant stress. Extracellular superoxide and hydroxyl radical were not involved in oxidant stress. Experiments with dimethyl sulfoxide showed that intracellular hydroxyl radical, generated from H(2)O(2), was the hemolytic agent. Neither methemoglobin formation nor lipid peroxidation involved hydroxyl radical. Indeed, lipid peroxidation and hemolysis in RBC from vitamin E-deficient rats were concurrent rather than consecutive events. Phase contrast microscopy showed that rigid, crenated RBC with a precipitate around the interior periphery formed during glutathione-induced oxidant stress. The precipitate dissolved slowly as the crenated RBC were converted to smooth ghosts. It appeared that protein precipitates involving mixed disulfide bonds were reduced and solubilized when extracellular glutathione penetrated the ruptured cell. Comparisons between normal RBC and vitamin E-deficient RBC suggest that vitamin E has little effect on the inward diffusion of extra-cellular H(2)O(2). Vitamin E apparently interacts with different oxidant species derived from intracellular H(2)O(2) in preventing lipid peroxidation and the sulfhydryl group oxidation leading to hemolysis.
将正常大鼠和维生素E缺乏大鼠的红细胞置于pH值为8的还原型谷胱甘肽高渗溶液中进行孵育。正常大鼠和维生素E缺乏大鼠的完整红细胞均出现高铁血红蛋白的形成。维生素E缺乏大鼠的红细胞溶血现象明显更严重。用过氧化氢酶、超氧化物歧化酶和甲硫醛进行的实验表明，H₂O₂是氧化应激的主要细胞外来源。细胞外超氧化物和羟基自由基不参与氧化应激。用二甲基亚砜进行的实验表明，由H₂O₂产生的细胞内羟基自由基是溶血剂。高铁血红蛋白的形成和脂质过氧化均不涉及羟基自由基。实际上，维生素E缺乏大鼠红细胞中的脂质过氧化和溶血是同时发生的，而非相继发生。相差显微镜显示，在谷胱甘肽诱导的氧化应激过程中，形成了内部周边有沉淀的僵硬、皱缩红细胞。当皱缩红细胞转变为光滑的血影时，沉淀会缓慢溶解。似乎当细胞外谷胱甘肽穿透破裂细胞时，涉及混合二硫键的蛋白质沉淀会被还原并溶解。正常红细胞与维生素E缺乏红细胞之间的比较表明，维生素E对细胞外H₂O₂的向内扩散影响很小。维生素E显然在防止脂质过氧化和导致溶血的巯基氧化过程中，与细胞内H₂O₂衍生的不同氧化物种相互作用。
