Hebbel R P, Eaton J W, Balasingam M, Steinberg M H
J Clin Invest. 1982 Dec;70(6):1253-9. doi: 10.1172/jci110724.
Since the various membrane abnormalities of sickle erythrocytes might result from excessive accumulation of oxidant damage, we have measured the generation of superoxide, peroxide, and hydroxyl radical by normal and sickle erythrocytes using assays involving reduction of cytochrome c, aminotriazole inhibition of catalase, and methane evolution from dimethyl sulfoxide, respectively. Compared with normal erythrocytes, sickle erythrocytes spontaneously generate approximately twice as much superoxide, peroxide, and hydroxyl radical. One possible source of hydroxyl radical generation was identified as hemichrome, excessive amounts of which are bound to sickle erythrocyte membranes. Hemichrome did not generate hydroxyl radical when exposed to superoxide alone or peroxide alone. However, in the presence of both superoxide and peroxide, hemichrome greatly facilitated hydroxyl radical generation. Supporting this, normal erythrocyte membranes induced to acquire sickle hemichrome concomitantly acquired an enhanced ability to mediate hydroxyl radical generation. Finally, sickle erythrocyte membranes greatly enhanced superoxide/peroxide-driven hydroxyl radical generation as compared with normal erythrocyte membranes. These data suggest that an excessive accumulation of oxidant damage in sickle erythrocyte membranes might contribute to the accelerated membrane senescence of these cells. They further indicate that accumulation of oxidant damage could be a determinant of normal erythrocyte membrane senescence.
由于镰状红细胞的各种膜异常可能是由于氧化损伤的过度积累所致，我们分别使用涉及细胞色素c还原、过氧化氢酶的氨基三唑抑制以及二甲基亚砜产生甲烷的测定方法，测量了正常红细胞和镰状红细胞中超氧化物、过氧化物和羟基自由基的生成情况。与正常红细胞相比，镰状红细胞自发产生的超氧化物、过氧化物和羟基自由基大约是正常红细胞的两倍。已确定羟基自由基产生的一个可能来源是高铁血红素，其过量存在于镰状红细胞膜上。当单独暴露于超氧化物或过氧化物时，高铁血红素不会产生羟基自由基。然而，在同时存在超氧化物和过氧化物的情况下，高铁血红素极大地促进了羟基自由基的产生。与此相符的是，诱导正常红细胞膜获得镰状高铁血红素后，其介导羟基自由基产生的能力也随之增强。最后，与正常红细胞膜相比，镰状红细胞膜极大地增强了超氧化物/过氧化物驱动的羟基自由基产生。这些数据表明，镰状红细胞膜中氧化损伤的过度积累可能导致这些细胞的膜衰老加速。它们还进一步表明，氧化损伤的积累可能是正常红细胞膜衰老的一个决定因素。
