Changes in gene expression level for defense system enzymes against oxidative stress and glutathione level in rat administered paraquat.
Changes in gene expression level for defense system enzymes against oxidative stress and glutathione level in rat administered paraquat.
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DOI：
10.3892/ijmm.15.4.689
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发表时间：
2005-04
影响因子：
5.4
通讯作者：
M. Tomita;H. Katsuyama;T. Okuyama;Kazuo Hidaka;Y. Minatogawa
中科院分区：
文献类型：
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作者：
M. Tomita;H. Katsuyama;T. Okuyama;Kazuo Hidaka;Y. Minatogawa
除草剂百草枯(PQ)在酶的活化过程中形成活性氧。我们检测了PQ对暴露于20 mg/kg PQ的大鼠肺部抗氧化酶基因表达和谷胱甘肽（GSH）状态的相对水平的影响。在摄入PQ后16 h，谷胱甘肽还原酶（GR） mRNA表达量增幅最大，过氧化氢酶（CAT）和锰超氧化物歧化酶（MnSOD） mRNA表达量增幅较小。相比之下，PQ对铜/锌超氧化物歧化酶（CuZnSOD）和谷胱甘肽过氧化物酶（GPX） mrna水平的影响很小或没有影响。这些结果表明，CAT和MnSOD是协调的，在去除氧化剂中起主要作用。另一方面，PQ引起肺中谷胱甘肽水平的显著增加，但在肝脏中没有。肺部的增加至少部分是由γ -谷氨酰半胱氨酸合成酶基因的刺激引起的。然而，GPX mRNA的表达未如上所述受到刺激。由于GSH是GPX的底物，并作为羟基自由基的清除剂，GSH和GR表达的增加可能不显著。这种不平衡可能是PQ引起的氧化应激的结果。
The herbicide paraquat (PQ) forms reactive oxygen species during enzymatic activation. We examined the effect of PQ on the relative levels of gene expression of antioxidant enzymes and glutathione (GSH) status in lungs of rats exposed to 20 mg/kg PQ. At 16 h after PQ intake, the mRNA expression level of glutathione reductase (GR) showed the greatest increase, and those of catalase (CAT) and manganese-superoxide dismutase (MnSOD) showed more modest increases. In contrast, PQ had little or no effect on the levels of mRNAs for copper/zinc-superoxide dismutase (CuZnSOD) and glutathione peroxidase (GPX). These findings indicate that CAT and MnSOD are coordinated and play a major role in removal of oxidants. On the other hand, PQ caused a significant increase in the GSH level in the lungs, but not in the liver. This increase in the lungs was, at least in part, caused by stimulation of the gamma-glutamylcysteine synthetase gene. However, the expression of GPX mRNA was not stimulated as described above. Because GSH is a substrate for GPX and serves as a scavenger of hydroxyl radicals, the increase in GSH as well as GR expression may be insignificant. This imbalance may be a result of oxidative stress due to PQ.