Chen M J, Sorette M P, Chiu D T, Clark M R
Center for Advanced Medical Technology, San Francisco State University, CA.
Biochim Biophys Acta. 1991 Jul 22;1066(2):193-200. doi: 10.1016/0005-2736(91)90186-c.
To provide further understanding of how oxidative damage affects red cell membrane function, the effects of low levels of two different types of oxidants on selected red cell properties have been studied. Hydrogen peroxide (H2O2), an example of a water soluble oxidant, and t-butylhydroperoxide (tBHP), a hydrophobic hydroperoxide, were compared with respect to their effects on membrane permeability, membrane mechanical properties and binding of autologous serum antibodies to the cell surface. Whereas H2O2 treatment resulted in a dose-dependent increase in membrane permeability to potassium that was evident after one hour of oxidant exposure, cells treated with tBHP at doses up to 5 mumol/ml cells showed no immediate change in cation permeability. H2O2 also caused a marked decrease in membrane deformability, whereas tBHP-treated cells showed minimal loss of deformability. However, tBHP treatment did result in a dose-dependent increase in the susceptibility of the membrane to fragmentation under high shear stress. With exclusion of treated samples that bound excess rabbit anti-spectrin antibody, indicating exposure of intracellular components, neither agent promoted the binding of autologous serum antibody in amounts comparable to that found in vivo on high density or some pathologic red cells. Taken together, the results suggest that tBHP and H2O2 cause damage to human red cells by distinct oxidative mechanisms which do not lead directly to substantive generation of binding sites for autologous serum antibodies.
为了进一步了解氧化损伤如何影响红细胞膜功能,研究了低水平的两种不同类型氧化剂对选定红细胞特性的影响。比较了水溶性氧化剂过氧化氢(H2O2)和疏水性氢过氧化物叔丁基过氧化氢(tBHP)对膜通透性、膜力学性能以及自体血清抗体与细胞表面结合的影响。H2O2处理导致膜对钾的通透性呈剂量依赖性增加,在氧化剂暴露1小时后即可明显观察到,而用高达5 μmol/ml细胞的tBHP处理的细胞阳离子通透性没有立即变化。H2O2还导致膜变形性显著降低,而tBHP处理的细胞变形性损失最小。然而,tBHP处理确实导致膜在高剪切应力下破碎敏感性呈剂量依赖性增加。排除与过量兔抗血影蛋白抗体结合的处理样本(表明细胞内成分暴露)后,两种试剂均未促进自体血清抗体的结合,其结合量与在高密度或某些病理性红细胞上体内发现的量相当。综上所述,结果表明tBHP和H2O2通过不同的氧化机制对人红细胞造成损伤,这些机制不会直接导致自体血清抗体结合位点的大量产生。