Primaquine-induced hemolytic anemia: Formation of free radicals in rat erythrocytes exposed to 6-methoxy-8-hydroxylaminoquinoline
Primaquine-induced hemolytic anemia: Formation of free radicals in rat erythrocytes exposed to 6-methoxy-8-hydroxylaminoquinoline
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DOI：
10.1124/jpet.102.041459
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发表时间：
2002-12-01
影响因子：
3.5
通讯作者：
McMillan, DC
中科院分区：
文献类型：
--
作者：
Bolchoz, LJC;Gelasco, AK;McMillan, DC
伯氨喹是一种重要的抗疟药物，在治疗中常常因溶血性贫血发作而受到剂量限制。我们最近已经表明，伯氨喹的N-羟基代谢产物，6-甲氧基-8-羟基氨基喹啉（MAQ-NOH），是一种直接作用于大鼠红细胞的溶血剂，这种代谢产物的溶血活性与GSH氧化和氧化损伤膜脂质和骨骼蛋白。为了确定自由基的形成是否可能参与该过程，将大鼠红细胞（40%悬浮液）与溶血浓度的MAQ-NOH（150-750 μ M）一起孵育，并使用2-乙氧羰基-2-甲基-3，4-二氢-2H-吡咯-1-氧化物（EMPO）作为自旋捕集器通过EPR光谱进行检查。MAQ-NOH添加到含有10 mM EMPO的红细胞悬液中产生了EPR光谱，其超精细常数与EMPO-羟基自由基加合物标准品一致。感兴趣的是，EMPO-OH的形成是恒定的长达20分钟，并依赖于红细胞GSH的存在。虽然没有其他自由基加合物的信号被检测到在细胞中的EPR，分光光度分析显示存在的铁血红蛋白，这表明过氧化氢是在这些实验条件下产生的。这些数据支持氧衍生的和可能的其他自由基参与MAQ-NOH诱导的溶血性贫血的机制的假设。
Primaquine is an important antimalarial drug that is often dose-limited in therapy by the onset of hemolytic anemia. We have shown recently that an N-hydroxy metabolite of primaquine, 6-methoxy-8-hydroxylaminoquinoline (MAQ-NOH), is a direct-acting hemolytic agent in rat red cells and that the hemolytic activity of this metabolite is associated with GSH oxidation and oxidative damage to both membrane lipids and skeletal proteins. To determine whether the formation of free radicals may be involved in this process, rat red cells (40% suspensions) were incubated with hemolytic concentrations of MAQ-NOH (150-750 muM) and examined by EPR spectroscopy using 2-ethoxycarbonyl-2-methyl-3,4-dihydro-2H-pyrrole-1-oxide (EMPO) as a spin trap. Addition of MAQ-NOH to red cell suspensions containing 10 mM EMPO gave rise to an EPR spectrum with hyperfine constants consistent with those of an EMPO-hydroxyl radical adduct standard. Of interest, formation of EMPO-OH was constant for up to 20 min and dependent on the presence of erythrocytic GSH. Although no other radical adduct signals were detected in the cells by EPR, spectrophotometric analysis revealed the presence of ferrylhemoglobin, which indicates that hydrogen peroxide is generated under these experimental conditions. The data support the hypothesis that oxygen-derived and possibly other free radicals are involved in the mechanism underlying MAQ-NOH-induced hemolytic anemia.