Paraquat- and diquat-induced oxygen radical generation and lipid peroxidation in rat brain microsomes.
Paraquat- and diquat-induced oxygen radical generation and lipid peroxidation in rat brain microsomes.
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DOI：
10.1093/oxfordjournals.jbchem.a003135
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发表时间：
2002-04
影响因子：
2.7
通讯作者：
K. Yumino;I. Kawakami;M. Tamura;Takaaki Hayashi;Masao Nakamura
中科院分区：
文献类型：
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作者：
K. Yumino;I. Kawakami;M. Tamura;Takaaki Hayashi;Masao Nakamura
NADPH甲萘醌还原酶活性的大鼠脑微粒体（MS）减少40-50%，由10 μ M双香豆素，一种有效的抑制剂DT-黄递酶，而没有变化的NADPH-百草枯（PQ）和-敌草快（DQ）还原酶活性观察。MS脑中NADPH-DQ还原酶活性是NADPH-PQ还原酶活性的2.5倍。PQ和DQ自由基的形成进行了光学验证，并直接观察到ESR波谱在NADPH-PQ和-DQ还原酶反应的大脑MS在厌氧条件下。PQ-和DQ-诱导的超氧化物形成通过检测DMPO-OOH ESR信号和随后的Cypridina lactoin类似物（CLA）的化学发光（CL）来证实。CL的动力学和强度与DQ的降低比PQ快的观察结果一致。在NADPH和Fe ~（3+）存在下，脑MS中的硫代巴比妥酸反应物质（TBARS）和磷脂过氧化氢增加。随着PQ和DQ浓度的增加，来自脑MS的脂质过氧化产物的产生减少。DQ的抑制作用比PQ更明显。PQ和DQ诱导的活性氧自由基的形成与大鼠脑中的脂质过氧化无关。
NADPH-menadione reductase activity by rat brain microsomes (Ms) was decreased 40-50% by 10 microM dicumarol, a potent inhibitor of DT-diaphorase, whereas no change in NADPH-paraquat (PQ) and -diquat (DQ) reductase activity was observed. NADPH-DQ reductase activity in brain Ms was 2.5-fold higher than NADPH-PQ reductase activity. The formation of PQ and DQ radicals was verified optically and observed directly by ESR spectroscopy in the NADPH-PQ and -DQ reductase reactions by brain Ms under anaerobic conditions. PQ- and DQ-induced superoxide formation was confirmed by the detection of DMPO-OOH ESR signals and followed by chemiluminescence (CL) of a Cypridina luciferin analogue (CLA). The kinetics and intensity of the CL were consistent with the observations that the reduction in DQ is faster than that in PQ. Thiobarbituric acid reactive substances (TBARS) and phospholipid hydroperoxides in brain Ms increased in the presence of NADPH and Fe3+. The generation of both lipid peroxidation products derived from brain Ms decreased with increasing concentrations of PQ and DQ. The inhibitory effect of DQ is more pronounced than that of PQ. The formation of PQ- and DQ-induced reactive oxygen species was not associated with lipid peroxidation in rat brain Ms.